diff --git a/docs/.vitepress/config.mts b/docs/.vitepress/config.mts
index 9f6a58e..9720265 100644
--- a/docs/.vitepress/config.mts
+++ b/docs/.vitepress/config.mts
@@ -162,6 +162,7 @@ export default withMermaid({
{ text: 'FLAC', link: '/codec-registry/flac' },
{ text: 'AC-3', link: '/codec-registry/ac3' },
{ text: 'E-AC-3', link: '/codec-registry/eac3' },
+ { text: 'DTS', link: '/codec-registry/dts' },
{ text: 'Linear PCM', link: '/codec-registry/pcm' },
{ text: 'μ-law PCM', link: '/codec-registry/ulaw' },
{ text: 'A-law PCM', link: '/codec-registry/alaw' },
diff --git a/docs/codec-registry/dts.md b/docs/codec-registry/dts.md
new file mode 100644
index 0000000..3f0d5b6
--- /dev/null
+++ b/docs/codec-registry/dts.md
@@ -0,0 +1,44 @@
+---
+description: DTS (DTS Coherent Acoustics) audio codec definition, defining legal codec strings, decoder configs, and packet data formats.
+---
+
+
+
+
+
+# DTS codec registration
+
+## Description
+
+The DTS audio codec (DTS Coherent Acoustics), specified in [ETSI TS 102 114](https://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.06.01_60/ts_102114v010601p.pdf).
+
+## Codec ID
+
+```ts
+'dts'
+```
+
+## `EncodedPacket` data
+
+The packet's data must be a core substream frame as defined in Section 5 of [ETSI TS 102 114](https://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.06.01_60/ts_102114v010601p.pdf), beginning with the sync word `0x7FFE8001`, followed by any number of extension substreams as defined in Section 7.4.1 of [ETSI TS 102 114](https://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.06.01_60/ts_102114v010601p.pdf), each beginning with the sync word `0x64582025`. The core substream frame may be omitted.
+
+The bitstream must use 16-bit big-endian packing.
+
+## `EncodedPacket` type
+
+The packet's type is always `'key'`.
+
+## `AudioDecoderConfig` codec string
+
+The codec string must be one of the four four-character codes identifying which substreams the bitstream is built from:
+
+- `'dtsc'` - a core substream only
+- `'dtsh'` - a core substream with extension substreams
+- `'dtsl'` - extension substreams carrying lossless audio, with no core substream
+- `'dtse'` - DTS Express
+
+## `AudioDecoderConfig` description
+
+`description` is not used for this codec.
diff --git a/docs/codec-registry/overview.md b/docs/codec-registry/overview.md
index bae0fb4..85e5b27 100644
--- a/docs/codec-registry/overview.md
+++ b/docs/codec-registry/overview.md
@@ -26,6 +26,7 @@ The registry is an extension of the [WebCodecs Codec Registry](https://www.w3.or
- [FLAC](./flac)
- [AC-3](./ac3)
- [E-AC-3](./eac3)
+- [DTS](./dts)
- [Linear PCM](./pcm)
- [μ-law PCM](./ulaw)
- [A-law PCM](./alaw)
diff --git a/docs/guide/extensions/server.md b/docs/guide/extensions/server.md
index 9d3754a..aec0681 100644
--- a/docs/guide/extensions/server.md
+++ b/docs/guide/extensions/server.md
@@ -8,7 +8,7 @@ By default, Mediabunny requires a browser environment for full access to decoder
Features added by this package include:
- Video decoders and encoders for AVC (H.264), HEVC (H.265), VP8, VP9, AV1, and ProRes. Supports both length-prefixed and Annex B AVC/HEVC as well as transparent video via VP9 and ProRes.
-- Audio decoders and encoders for AAC, MP3, Vorbis, Opus, FLAC, AC-3 and E-AC-3. Supports AAC in both AAC and ADTS formats.
+- Audio decoders and encoders for AAC, MP3, Vorbis, Opus, FLAC, AC-3, E-AC-3 and DTS. Supports AAC in both AAC and ADTS formats.
- Video frame transformation support (resize, rotate, crop)
- Automatic hardware acceleration on all platforms (macOS, Linux, Windows)
- Built-in multithreading
diff --git a/docs/guide/introduction.md b/docs/guide/introduction.md
index 0e66c84..d2ec32a 100644
--- a/docs/guide/introduction.md
+++ b/docs/guide/introduction.md
@@ -64,7 +64,7 @@ Mediabunny's simple yet flexible API provides a modern alternative to traditiona
The extension enables:
- Video decoders and encoders for AVC (H.264), HEVC (H.265), VP8, VP9, and AV1. Supports both length-prefixed and Annex B AVC/HEVC as well as transparent video via VP9.
-- Audio decoders and encoders for AAC, MP3, Vorbis, Opus, FLAC, AC-3 and E-AC-3. Supports AAC in both AAC and ADTS formats.
+- Audio decoders and encoders for AAC, MP3, Vorbis, Opus, FLAC, AC-3, E-AC-3 and DTS. Supports AAC in both AAC and ADTS formats.
- Video frame transformation support (resize, rotate, crop)
- Automatic hardware acceleration on all platforms (macOS, Linux, Windows)
- Built-in multithreading
diff --git a/docs/guide/supported-formats-and-codecs.md b/docs/guide/supported-formats-and-codecs.md
index d420bf0..6158de2 100644
--- a/docs/guide/supported-formats-and-codecs.md
+++ b/docs/guide/supported-formats-and-codecs.md
@@ -51,6 +51,7 @@ Mediabunny ships with built-in decoders and encoders for all audio PCM codecs, m
- `'flac'` - Free Lossless Audio Codec (FLAC) [^flac]
- `'ac3'` - Dolby Digital (AC-3) [^ac3]
- `'eac3'` - Dolby Digital Plus (E-AC-3) [^ac3]
+- `'dts'` - DTS Coherent Acoustics [^dts]
- `'pcm-u8'` - 8-bit unsigned PCM
- `'pcm-s8'` - 8-bit signed PCM
- `'pcm-s16'` - 16-bit little-endian signed PCM
@@ -89,6 +90,7 @@ Not all codecs can be used with all containers. The following table specifies th
| `'flac'` | ✓ | ✓ | ✓ | | | | | | ✓ | |
| `'ac3'` | ✓ | ✓ | ✓ | | | | | | | ✓ |
| `'eac3'` | ✓ | ✓ | ✓ | | | | | | | ✓ |
+| `'dts'` | ✓ | ✓ | ✓ | | | | | | | ✓ |
| `'pcm-u8'` | | ✓ | ✓ | | | | ✓ | | | |
| `'pcm-s8'` | | ✓ | | | | | | | | |
| `'pcm-s16'` | ✓ | ✓ | ✓ | | | | ✓ | | | |
@@ -112,6 +114,7 @@ For HLS, the supported codecs depend on the segment format chosen.
[^mp3]: MP3 encoding is not supported by WebCodecs. You can polyfill it with the [`@mediabunny/mp3-encoder`](./extensions/mp3-encoder) extension package.
[^flac]: FLAC encoding is not supported by WebCodecs. You can polyfill it with the [`@mediabunny/flac-encoder`](./extensions/flac-encoder) extension package.
[^ac3]: AC-3 and E-AC-3 are not natively supported by WebCodecs. To encode or decode these codecs, you can use the [`@mediabunny/ac3`](./extensions/ac3) extension package.
+[^dts]: DTS is not supported by WebCodecs. The [`@mediabunny/server`](./extensions/server) extension package provides both decoding and encoding support for server-side environments.
[^webm]: WebM only supports a small subset of the codecs supported by Matroska. However, this library can technically read all codecs from a WebM that are supported by Matroska.
[^webvtt]: WebVTT can only be written, not read.
@@ -127,7 +130,7 @@ import { canEncode } from 'mediabunny';
canEncode('avc'); // => Promise
canEncode('opus'); // => Promise
```
-Video codecs are checked using 1280x720 @1Mbps, while audio codecs are checked using 2 channels, 48 kHz @128kbps.
+Video codecs are checked using 1280x720, while audio codecs are checked using 2 channels at 48 kHz.
You can also check encodability using specific configurations:
```ts
diff --git a/packages/server/src/audio-decoder.ts b/packages/server/src/audio-decoder.ts
index 22bb420..247d16b 100644
--- a/packages/server/src/audio-decoder.ts
+++ b/packages/server/src/audio-decoder.ts
@@ -25,7 +25,8 @@ export class NodeAvAudioDecoder extends CustomAudioDecoder {
|| codec === 'vorbis'
|| codec === 'flac'
|| codec === 'ac3'
- || codec === 'eac3';
+ || codec === 'eac3'
+ || codec === 'dts';
}
async init(): Promise {
diff --git a/packages/server/src/audio-encoder.ts b/packages/server/src/audio-encoder.ts
index 9b94106..172a0f5 100644
--- a/packages/server/src/audio-encoder.ts
+++ b/packages/server/src/audio-encoder.ts
@@ -15,7 +15,7 @@ import {
EncodedPacket,
} from 'mediabunny';
import * as NodeAv from 'node-av';
-import { CODEC_TO_CODEC_ID, getChannelLayout } from './misc';
+import { CODEC_TO_CODEC_ID, getChannelLayout, getDtsChannelLayout } from './misc';
import { assert, toUint8Array } from '../../../src/misc';
import { copyAudioSampleToAvFrame, AvFrameAudioSampleResource } from './audio-sample';
import {
@@ -29,6 +29,11 @@ const AAC_SAMPLE_RATES
const OPUS_SAMPLE_RATES = [8000, 12000, 16000, 24000, 48000];
const MP3_SAMPLE_RATES = [8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000];
const AC3_SAMPLE_RATES = [32000, 44100, 48000];
+const DTS_SAMPLE_RATES = [8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000];
+
+/** DTS only has layouts for these channel counts; 3 and 7 have no mapping. */
+const DTS_CHANNEL_COUNTS = [1, 2, 4, 5, 6];
+const DTS_MAX_FRAME_SIZE = 16384;
const FRAME_SIZE_FALLBACK = 1024; // Just 'cause
@@ -72,6 +77,10 @@ export class NodeAvAudioEncoder extends CustomAudioEncoder {
) || (
codec === 'eac3' && numberOfChannels >= 1 && numberOfChannels <= 16
&& AC3_SAMPLE_RATES.includes(sampleRate)
+ ) || (
+ codec === 'dts' && DTS_CHANNEL_COUNTS.includes(numberOfChannels)
+ && DTS_SAMPLE_RATES.includes(sampleRate)
+ && dtsBitrateFits(resolveBitrate(config, codec), sampleRate, numberOfChannels)
);
}
@@ -107,21 +116,26 @@ export class NodeAvAudioEncoder extends CustomAudioEncoder {
}
codecContext.sampleRate = this.config.sampleRate;
- codecContext.channelLayout = getChannelLayout(this.config.numberOfChannels);
+ codecContext.channelLayout = this.codec === 'dts'
+ ? getDtsChannelLayout(this.config.numberOfChannels)
+ : getChannelLayout(this.config.numberOfChannels);
codecContext.codecType = NodeAv.AVMEDIA_TYPE_AUDIO;
codecContext.codecId = CODEC_TO_CODEC_ID[this.codec]!;
codecContext.sampleFormat = sampleFormat;
codecContext.timeBase = new NodeAv.Rational(1, this.config.sampleRate);
- codecContext.bitRate = BigInt(
- this.config.bitrate ?? new Quality('medium')._toAudioBitrate(this.codec) ?? 0,
- );
+ codecContext.bitRate = BigInt(resolveBitrate(this.config, this.codec));
if (this.config.bitrateMode === 'constant') {
codecContext.rcMinRate = codecContext.bitRate;
codecContext.rcMaxRate = codecContext.bitRate;
}
- const ret = await codecContext.open2();
+ // libav's DTS encoder is marked experimental, so it refuses to open at the default compliance level
+ const options = this.codec === 'dts'
+ ? NodeAv.Dictionary.fromObject({ strict: -2 })
+ : null;
+
+ const ret = await codecContext.open2(this.avCodec, options);
NodeAv.FFmpegError.throwIfError(ret, 'Open codec context');
this.codecContext = codecContext;
@@ -172,7 +186,9 @@ export class NodeAvAudioEncoder extends CustomAudioEncoder {
this.resampler = new NodeAv.SoftwareResampleContext();
this.resamplerInputSampleRate = this.frame.sampleRate;
- const outLayout = getChannelLayout(this.codecContext.channels);
+ // Resample straight to whatever layout the encoder was opened with, since not every codec accepts
+ // the layout that getChannelLayout hands out for a given channel count
+ const outLayout = this.codecContext.channelLayout;
const inLayout = getChannelLayout(this.frame.channels);
const ret = this.resampler.allocSetOpts2(
@@ -400,3 +416,25 @@ export class NodeAvAudioEncoder extends CustomAudioEncoder {
this.resampler?.free();
}
}
+
+const resolveBitrate = (config: AudioEncoderConfig, codec: AudioCodec) => {
+ return config.bitrate ?? new Quality('medium')._toAudioBitrate(codec) ?? 0;
+};
+
+/**
+ * The DTS encoder needs each frame to be big enough to hold the per-channel side info and rejects the whole
+ * configuration when it isn't, so this mirrors the check from FFmpeg's dcaenc.c.
+ */
+const dtsBitrateFits = (bitrate: number, sampleRate: number, numberOfChannels: number) => {
+ if (bitrate < 32000 || bitrate > 3840000) {
+ return false;
+ }
+
+ const hasLfe = numberOfChannels === 6;
+ const fullbandChannels = numberOfChannels - (hasLfe ? 1 : 0);
+
+ const frameBits = 32 * Math.ceil(Math.ceil(bitrate * 512 / sampleRate) / 32);
+ const minFrameBits = 132 + (493 + 28 * 32) * fullbandChannels + (hasLfe ? 72 : 0);
+
+ return frameBits >= minFrameBits && frameBits <= 8 * DTS_MAX_FRAME_SIZE;
+};
diff --git a/packages/server/src/misc.ts b/packages/server/src/misc.ts
index 3c152ae..ab4998a 100644
--- a/packages/server/src/misc.ts
+++ b/packages/server/src/misc.ts
@@ -25,6 +25,7 @@ export const CODEC_TO_CODEC_ID: Partial> =
flac: NodeAv.AV_CODEC_ID_FLAC,
ac3: NodeAv.AV_CODEC_ID_AC3,
eac3: NodeAv.AV_CODEC_ID_EAC3,
+ dts: NodeAv.AV_CODEC_ID_DTS,
};
let cachedHardwareContext: NodeAv.HardwareContext | null | undefined = undefined;
@@ -267,3 +268,21 @@ export const getChannelLayout = (numChannels: number): NodeAv.ChannelLayout => {
default: return { nbChannels: numChannels, order: NodeAv.AV_CHANNEL_ORDER_UNSPEC, mask: 0n };
}
};
+
+/** FL + FR + SL + SR, which libav has no constant for. */
+const QUAD_SIDE_MASK = 0x603n;
+
+/**
+ * DTS insists on the side-based surround layouts and rejects the back-based ones that {@link getChannelLayout}
+ * hands out, so it gets its own mapping.
+ */
+export const getDtsChannelLayout = (numChannels: number): NodeAv.ChannelLayout => {
+ switch (numChannels) {
+ case 1: return NodeAv.AV_CHANNEL_LAYOUT_MONO;
+ case 2: return NodeAv.AV_CHANNEL_LAYOUT_STEREO;
+ case 4: return { nbChannels: 4, order: NodeAv.AV_CHANNEL_ORDER_NATIVE, mask: QUAD_SIDE_MASK };
+ case 5: return NodeAv.AV_CHANNEL_LAYOUT_5POINT0;
+ case 6: return NodeAv.AV_CHANNEL_LAYOUT_5POINT1;
+ default: return { nbChannels: numChannels, order: NodeAv.AV_CHANNEL_ORDER_UNSPEC, mask: 0n };
+ }
+};
diff --git a/src/codec-data.ts b/src/codec-data.ts
index 8319af3..071720d 100644
--- a/src/codec-data.ts
+++ b/src/codec-data.ts
@@ -6,7 +6,7 @@
* file, You can obtain one at https://mozilla.org/MPL/2.0/.
*/
-import { AVC_LEVEL_TABLE, VideoCodec, VP9_LEVEL_TABLE } from './codec';
+import { AVC_LEVEL_TABLE, DtsFourCc, VideoCodec, VP9_LEVEL_TABLE } from './codec';
import {
assert,
assertNever,
@@ -24,6 +24,7 @@ import {
toUint8Array,
getChromiumVersion,
isChromium,
+ popcount,
setUint24,
} from './misc';
import { Logging } from './logging';
@@ -3176,3 +3177,495 @@ export const getEac3ChannelCount = (config: Eac3FrameInfo): number => {
return channels;
};
+
+// ============================================================================
+// DTS Parsing
+// Reference: ETSI TS 102 114 V1.6.1
+// ============================================================================
+
+/** Core substream sync word, in the 16-bit big-endian packing that the registry mandates. */
+export const DTS_CORE_SYNC_WORD = 0x7ffe8001;
+
+/** Extension substream sync word. Section 7.4.1 */
+export const DTS_EXSS_SYNC_WORD = 0x64582025;
+
+/** The core frame header never reaches beyond this many bytes. */
+export const DTS_CORE_FRAME_HEADER_SIZE = 18;
+
+/** An extension substream always declares its own size within this many bytes. */
+export const DTS_EXSS_HEADER_PREFIX_SIZE = 10;
+
+/** The largest nuExtSSHeaderSize can get, and therefore how far the asset descriptors can reach. */
+export const DTS_EXSS_MAX_HEADER_SIZE = 4096;
+
+/** Number of PCM samples in one core PCM block; the core codes its length as a count of these. */
+export const DTS_PCM_BLOCK_SAMPLES = 32;
+
+/** Size of the DTSSpecificBox (ddts) payload in bytes. */
+export const DTS_SPECIFIC_BOX_SIZE = 20;
+
+/** Number of PCM blocks that a core frame's length must be a multiple of. */
+const DTS_SUBBAND_SAMPLES = 8;
+
+/** Core sample rates indexed by SFREQ. Zeroes mark invalid codes. Table 5-4 */
+const DTS_CORE_SAMPLE_RATES = [
+ 0, 8000, 16000, 32000, 0, 0, 11025, 22050,
+ 44100, 0, 0, 12000, 24000, 48000, 96000, 192000,
+];
+
+/**
+ * Core bit rates in bps indexed by RATE, where a zero means the code isn't a constant rate. Table 5-7
+ *
+ * Note that FFmpeg's ff_dca_bit_rates has 896000 where the spec has 960, and defines rates for codes 25 to 28
+ * which this revision of the spec calls invalid. We keep the latter, since they cost nothing and some content
+ * predating the spec revision uses them.
+ */
+const DTS_CORE_BIT_RATES = [
+ 32000, 56000, 64000, 96000, 112000, 128000, 192000, 224000,
+ 256000, 320000, 384000, 448000, 512000, 576000, 640000, 768000,
+ 960000, 1024000, 1152000, 1280000, 1344000, 1408000, 1411200, 1472000,
+ 1536000, 1920000, 2048000, 3072000, 3840000, 0, 0, 0,
+];
+
+/** Source PCM resolutions in bits indexed by PCMR. Zeroes mark invalid codes. */
+const DTS_PCM_RESOLUTIONS = [16, 16, 20, 20, 0, 24, 24, 0];
+
+/** Channel counts indexed by AMODE, not counting LFE. */
+const DTS_AMODE_CHANNEL_COUNTS = [1, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 6, 7, 8, 8];
+
+/**
+ * Speaker layout masks indexed by AMODE, expressed with the same bits as `ChannelLayout` in the DTSSpecificBox
+ * and `nuSpkrActivityMask` in an extension substream asset descriptor.
+ */
+const DTS_AMODE_CHANNEL_LAYOUTS = [
+ 0x0001, 0x0002, 0x0002, 0x0002, 0x0002, 0x0003, 0x0012, 0x0013,
+ 0x0006, 0x0007, 0x0206, 0x0143, 0x0053, 0x0207, 0x0246, 0x0217,
+];
+
+/** The LFE1 speaker bit in a channel layout mask. */
+const DTS_CHANNEL_LAYOUT_LFE1 = 0x0008;
+
+/** The channel layout bits that stand for a pair of speakers rather than a single one. */
+const DTS_CHANNEL_LAYOUT_PAIR_MASK = 0xae66;
+
+/** Reference clock rates indexed by nuRefClockCode. The last code is unused. Table 7-3 */
+const DTS_EXSS_REF_CLOCKS = [32000, 44100, 48000, 0];
+
+/** Sample rates used by extension substream assets, indexed by nuMaxSampleRate. */
+const DTS_EXSS_SAMPLE_RATES = [
+ 8000, 16000, 32000, 64000, 128000, 22050, 44100, 88200,
+ 176400, 352800, 12000, 24000, 48000, 96000, 192000, 384000,
+];
+
+/** Frame durations that the DTSSpecificBox can express, indexed by FrameDuration. */
+const DTS_SPECIFIC_BOX_FRAME_DURATIONS = [512, 1024, 2048, 4096];
+
+export type DtsCoreFrameInfo = {
+ /** Size of the core substream frame in bytes */
+ frameSize: number;
+ sampleRate: number;
+ numberOfChannels: number;
+ /** Number of PCM samples the frame decodes to */
+ sampleCount: number;
+ /** Speaker layout mask */
+ channelLayout: number;
+ /** Audio channel arrangement (AMODE) */
+ amode: number;
+ /** Whether an LFE channel is present */
+ lfePresent: boolean;
+ /** Constant bit rate in bps, or 0 when the stream doesn't run at one */
+ bitRate: number;
+ /** Source PCM resolution in bits */
+ pcmResolution: number;
+};
+
+export type DtsExssAssetInfo = {
+ sampleRate: number;
+ numberOfChannels: number;
+ /** Number of PCM samples the frame decodes to */
+ sampleCount: number;
+ /** Speaker layout mask, or 0 when the asset doesn't declare one */
+ channelLayout: number;
+ /** Source PCM resolution in bits */
+ pcmResolution: number;
+};
+
+export type DtsExssInfo = {
+ /** Size of the extension substream in bytes */
+ frameSize: number;
+ /** Null when this substream omits the static fields that describe the stream */
+ asset: DtsExssAssetInfo | null;
+};
+
+export type DtsFrameInfo = {
+ /** Size of the entire frame in bytes, core substream plus any extension substreams */
+ frameSize: number;
+ sampleRate: number;
+ numberOfChannels: number;
+ /** Number of PCM samples the frame decodes to */
+ sampleCount: number;
+ /** Speaker layout mask */
+ channelLayout: number;
+ /** Source PCM resolution in bits */
+ pcmResolution: number;
+ /** Constant bit rate in bps, or 0 when the stream doesn't run at one */
+ bitRate: number;
+ /** The leading core substream, or null for extension-only streams such as DTS Express */
+ core: DtsCoreFrameInfo | null;
+ /** Whether the frame carries extension substreams on top of the core */
+ hasExtensions: boolean;
+};
+
+/**
+ * Parse one complete DTS frame, being a core substream frame followed by any number of extension substreams,
+ * or an extension substream on its own. Section 5 and Section 7.4.1
+ */
+export const parseDtsFrame = (data: Uint8Array): DtsFrameInfo | null => {
+ const core = parseDtsCoreFrameHeader(data);
+ const view = toDataView(data);
+
+ // The core substream is padded out to a 4-byte boundary before the first extension substream starts
+ let offset = core ? Math.ceil(core.frameSize / 4) * 4 : 0;
+ let firstExss: DtsExssInfo | null = null;
+
+ while (offset + 4 <= data.length && view.getUint32(offset) === DTS_EXSS_SYNC_WORD) {
+ const exss = parseDtsExssHeader(data.subarray(offset));
+ if (!exss) {
+ break;
+ }
+
+ firstExss ??= exss;
+ offset += exss.frameSize;
+ }
+
+ if (core) {
+ // The core describes what every DTS decoder can play back; the extension substreams only build on top of
+ // it, so the core's parameters are the ones we report.
+ return {
+ frameSize: firstExss ? offset : core.frameSize,
+ sampleRate: core.sampleRate,
+ numberOfChannels: core.numberOfChannels,
+ sampleCount: core.sampleCount,
+ channelLayout: core.channelLayout,
+ pcmResolution: core.pcmResolution,
+ bitRate: core.bitRate,
+ core,
+ hasExtensions: firstExss !== null,
+ };
+ }
+
+ if (!firstExss?.asset) {
+ return null;
+ }
+
+ const { asset } = firstExss;
+
+ return {
+ frameSize: offset,
+ sampleRate: asset.sampleRate,
+ numberOfChannels: asset.numberOfChannels,
+ sampleCount: asset.sampleCount,
+ channelLayout: asset.channelLayout,
+ pcmResolution: asset.pcmResolution,
+ bitRate: 0,
+ core: null,
+ hasExtensions: true,
+ };
+};
+
+/**
+ * Works out which four-character code describes a packet, or null when the packet doesn't say. Telling 'dtsl'
+ * from 'dtse' would mean working out whether the asset holds XLL or LBR data, which sits behind the speaker
+ * remapping and mixing metadata deep in the asset descriptor, so we don't do it.
+ */
+export const extractDtsFourCcFromPacket = (data: Uint8Array): DtsFourCc | null => {
+ const frameInfo = parseDtsFrame(data);
+ if (!frameInfo?.core) {
+ return null;
+ }
+
+ return frameInfo.hasExtensions ? 'dtsh' : 'dtsc';
+};
+
+/** Parse the header of a core substream frame. Section 5.3 */
+export const parseDtsCoreFrameHeader = (data: Uint8Array): DtsCoreFrameInfo | null => {
+ if (data.length < DTS_CORE_FRAME_HEADER_SIZE) {
+ return null;
+ }
+ if (data[0] !== 0x7f || data[1] !== 0xfe || data[2] !== 0x80 || data[3] !== 0x01) {
+ return null;
+ }
+
+ const bitstream = new Bitstream(data);
+ bitstream.skipBits(32); // SYNC
+
+ bitstream.skipBits(1); // FTYPE
+
+ // Terminating frames carry fewer samples than a full PCM block; we don't handle those
+ if (bitstream.readBits(5) !== DTS_PCM_BLOCK_SAMPLES - 1) {
+ return null;
+ }
+
+ const cpf = bitstream.readBits(1);
+ const npcmblocks = bitstream.readBits(7) + 1;
+ if (npcmblocks % DTS_SUBBAND_SAMPLES !== 0) {
+ return null;
+ }
+
+ const frameSize = bitstream.readBits(14) + 1;
+ if (frameSize < 96) {
+ return null;
+ }
+
+ const amode = bitstream.readBits(6);
+ if (amode >= DTS_AMODE_CHANNEL_COUNTS.length) {
+ return null;
+ }
+
+ const sampleRate = DTS_CORE_SAMPLE_RATES[bitstream.readBits(4)]!;
+ if (sampleRate === 0) {
+ return null;
+ }
+
+ const bitRate = DTS_CORE_BIT_RATES[bitstream.readBits(5)]!;
+
+ if (bitstream.readBits(1) !== 0) {
+ return null; // A reserved bit that must be zero, so a cheap way to reject false sync words
+ }
+
+ bitstream.skipBits(1 + 1 + 1 + 1); // DYNF, TIMEF, AUXF, HDCD
+ bitstream.skipBits(3 + 1 + 1); // EXT_AUDIO_ID, EXT_AUDIO, ASPF
+
+ const lff = bitstream.readBits(2);
+ if (lff === 3) {
+ return null;
+ }
+
+ bitstream.skipBits(1); // HFLAG
+ if (cpf) {
+ bitstream.skipBits(16); // HCRC
+ }
+
+ bitstream.skipBits(1 + 4 + 2); // FILTS, VERNUM, CHIST
+
+ const pcmResolution = DTS_PCM_RESOLUTIONS[bitstream.readBits(3)]!;
+ if (pcmResolution === 0) {
+ return null;
+ }
+
+ const lfePresent = lff !== 0;
+
+ return {
+ frameSize,
+ sampleRate,
+ numberOfChannels: DTS_AMODE_CHANNEL_COUNTS[amode]! + (lfePresent ? 1 : 0),
+ sampleCount: npcmblocks * DTS_PCM_BLOCK_SAMPLES,
+ channelLayout: DTS_AMODE_CHANNEL_LAYOUTS[amode]! | (lfePresent ? DTS_CHANNEL_LAYOUT_LFE1 : 0),
+ amode,
+ lfePresent,
+ bitRate,
+ pcmResolution,
+ };
+};
+
+/** Parse the header of an extension substream, along with its first audio asset descriptor. Section 7.4.1 */
+export const parseDtsExssHeader = (data: Uint8Array): DtsExssInfo | null => {
+ if (data.length < DTS_EXSS_HEADER_PREFIX_SIZE) {
+ return null;
+ }
+ if (data[0] !== 0x64 || data[1] !== 0x58 || data[2] !== 0x20 || data[3] !== 0x25) {
+ return null;
+ }
+
+ const bitstream = new Bitstream(data);
+ bitstream.skipBits(32); // SYNC
+ bitstream.skipBits(8); // nuUserDefinedBits
+
+ const extSsIndex = bitstream.readBits(2);
+ const wideHeader = bitstream.readBits(1);
+ const headerSizeBits = 8 + 4 * wideHeader;
+ const frameSizeBits = 16 + 4 * wideHeader;
+
+ bitstream.skipBits(headerSizeBits); // nuExtSSHeaderSize
+ const frameSize = bitstream.readBits(frameSizeBits) + 1;
+
+ // Everything past this point can run off the end of what we were given, in which case the Bitstream keeps
+ // handing out zeroes; the bounds check further down catches that
+ const incomplete: DtsExssInfo = { frameSize, asset: null };
+
+ if (!bitstream.readBits(1)) { // bStaticFieldsPresent
+ return incomplete;
+ }
+
+ const refClock = DTS_EXSS_REF_CLOCKS[bitstream.readBits(2)]!; // nuRefClockCode
+ // The frame duration is a count of reference clock cycles, not of samples
+ const frameDurationCycles = 512 * (bitstream.readBits(3) + 1); // nuExSSFrameDurationCode
+
+ if (bitstream.readBits(1)) { // bTimeStampFlag
+ bitstream.skipBits(32 + 4); // nuTimeStamp, nLSB
+ }
+
+ const numAudioPresentations = bitstream.readBits(3) + 1;
+ const numAssets = bitstream.readBits(3) + 1;
+
+ const activeExssMasks: number[] = [];
+ for (let i = 0; i < numAudioPresentations; i++) {
+ activeExssMasks.push(bitstream.readBits(extSsIndex + 1));
+ }
+ for (const mask of activeExssMasks) {
+ bitstream.skipBits(8 * popcount(mask)); // nuActiveAssetMask
+ }
+
+ if (bitstream.readBits(1)) { // bMixMetadataEnbl
+ bitstream.skipBits(2); // nuMixMetadataAdjLevel
+ const spkrMaskBits = (bitstream.readBits(2) + 1) << 2;
+ const numMixOutConfigs = bitstream.readBits(2) + 1;
+ bitstream.skipBits(numMixOutConfigs * spkrMaskBits); // nuMixOutChMask
+ }
+
+ for (let i = 0; i < numAssets; i++) {
+ bitstream.skipBits(frameSizeBits); // nuAssetFsize
+ }
+
+ // From here on we're inside the first audio asset descriptor
+ bitstream.skipBits(9); // nuAssetDescriptFsize
+ bitstream.skipBits(3); // nuAssetIndex
+
+ if (bitstream.readBits(1)) { // bAssetTypeDescrPresent
+ bitstream.skipBits(4); // nuAssetTypeDescriptor
+ }
+ if (bitstream.readBits(1)) { // bLanguageDescrPresent
+ bitstream.skipBits(24); // LanguageDescriptor
+ }
+ if (bitstream.readBits(1)) { // bInfoTextPresent
+ bitstream.skipBits(8 * (bitstream.readBits(10) + 1)); // nuInfoTextByteSize, InfoTextString
+ }
+
+ const pcmResolution = bitstream.readBits(5) + 1;
+ const sampleRate = DTS_EXSS_SAMPLE_RATES[bitstream.readBits(4)]!;
+ const numberOfChannels = bitstream.readBits(8) + 1;
+
+ let channelLayout = 0;
+
+ if (bitstream.readBits(1)) { // bOne2OneMapChannels2Speakers
+ if (numberOfChannels > 2) {
+ bitstream.skipBits(1); // bEmbeddedStereoFlag
+ }
+ if (numberOfChannels > 6) {
+ bitstream.skipBits(1); // bEmbeddedSixChFlag
+ }
+
+ if (bitstream.readBits(1)) { // bSpkrMaskEnabled
+ const spkrMaskBits = (bitstream.readBits(2) + 1) << 2;
+ channelLayout = bitstream.readBits(spkrMaskBits); // nuSpkrActivityMask
+ }
+ }
+
+ if (refClock === 0 || bitstream.getBitsLeft() < 0) {
+ return incomplete;
+ }
+
+ return {
+ frameSize,
+ asset: {
+ sampleRate,
+ numberOfChannels,
+ sampleCount: Math.round(frameDurationCycles * sampleRate / refClock),
+ channelLayout,
+ pcmResolution,
+ },
+ };
+};
+
+export type DtsSpecificBoxInfo = {
+ sampleRate: number;
+ maxBitrate: number;
+ avgBitrate: number;
+ pcmSampleDepth: number;
+ /** Number of PCM samples one frame decodes to */
+ sampleCount: number;
+ /** Speaker layout mask, or 0 when the box doesn't declare one */
+ channelLayout: number;
+ /** Null when the box carries nothing we can derive a channel count from */
+ numberOfChannels: number | null;
+};
+
+/** Parse a DTSSpecificBox (ddts). */
+export const parseDtsSpecificBox = (data: Uint8Array): DtsSpecificBoxInfo | null => {
+ if (data.length < DTS_SPECIFIC_BOX_SIZE) {
+ return null;
+ }
+
+ const view = toDataView(data);
+ const sampleRate = view.getUint32(0);
+ if (sampleRate === 0) {
+ return null;
+ }
+
+ const bitstream = new Bitstream(data);
+ bitstream.seekToByte(13);
+
+ const frameDuration = bitstream.readBits(2);
+ bitstream.skipBits(5); // StreamConstruction
+ const coreLfePresent = bitstream.readBits(1);
+ const coreLayout = bitstream.readBits(6);
+ bitstream.skipBits(14); // CoreSize
+ bitstream.skipBits(1); // StereoDownmix
+ bitstream.skipBits(3); // RepresentationType
+ const channelLayout = bitstream.readBits(16);
+
+ let numberOfChannels: number | null = null;
+ if (channelLayout !== 0) {
+ numberOfChannels = getDtsChannelCount(channelLayout);
+ } else if (coreLayout < DTS_AMODE_CHANNEL_COUNTS.length) {
+ numberOfChannels = DTS_AMODE_CHANNEL_COUNTS[coreLayout]! + coreLfePresent;
+ }
+
+ return {
+ sampleRate,
+ maxBitrate: view.getUint32(4),
+ avgBitrate: view.getUint32(8),
+ pcmSampleDepth: data[12]!,
+ sampleCount: DTS_SPECIFIC_BOX_FRAME_DURATIONS[frameDuration]!,
+ channelLayout,
+ numberOfChannels,
+ };
+};
+
+/** Build the payload of a DTSSpecificBox (ddts) from a frame of the stream it describes. */
+export const buildDtsSpecificBox = (frameInfo: DtsFrameInfo) => {
+ const bytes = new Uint8Array(DTS_SPECIFIC_BOX_SIZE);
+ const view = toDataView(bytes);
+
+ view.setUint32(0, frameInfo.sampleRate);
+ view.setUint32(4, frameInfo.bitRate);
+ view.setUint32(8, frameInfo.bitRate);
+ bytes[12] = frameInfo.pcmResolution;
+
+ // The spec only defines codes for streams built out of a known set of substreams. Anything else is required
+ // to be signaled as 0, meaning the construction is left unspecified.
+ const streamConstruction = frameInfo.core && !frameInfo.hasExtensions ? 1 : 0;
+
+ const bitstream = new Bitstream(bytes);
+ bitstream.seekToByte(13);
+
+ bitstream.writeBits(2, Math.max(DTS_SPECIFIC_BOX_FRAME_DURATIONS.indexOf(frameInfo.sampleCount), 0));
+ bitstream.writeBits(5, streamConstruction);
+ bitstream.writeBits(1, frameInfo.core?.lfePresent ? 1 : 0);
+ bitstream.writeBits(6, frameInfo.core?.amode ?? 0);
+ bitstream.writeBits(14, frameInfo.core ? frameInfo.core.frameSize - 1 : 0);
+ bitstream.writeBits(1, 0); // StereoDownmix
+ bitstream.writeBits(3, 0); // RepresentationType
+ bitstream.writeBits(16, frameInfo.channelLayout);
+ bitstream.writeBits(1, 0); // MultiAssetFlag
+ bitstream.writeBits(1, 0); // LBRDurationMod
+ bitstream.writeBits(1, 0); // ReservedBoxPresent
+ bitstream.writeBits(5, 0); // Reserved
+
+ return bytes;
+};
+
+/** Count the channels in a DTS speaker layout mask, where some bits stand for a pair of speakers. */
+const getDtsChannelCount = (channelLayout: number) => {
+ return popcount(channelLayout) + popcount(channelLayout & DTS_CHANNEL_LAYOUT_PAIR_MASK);
+};
diff --git a/src/codec.ts b/src/codec.ts
index 08f1b52..63c41d1 100644
--- a/src/codec.ts
+++ b/src/codec.ts
@@ -75,6 +75,7 @@ export const NON_PCM_AUDIO_CODECS = [
'flac',
'ac3',
'eac3',
+ 'dts',
] as const;
/**
* List of known audio codecs, ordered by encoding preference.
@@ -227,6 +228,14 @@ export const PRORES_FOURCCS = [
] as const;
export type ProresFourCc = typeof PRORES_FOURCCS[number];
+export const DTS_FOURCCS = [
+ 'dtsc', // DTS core
+ 'dtsh', // DTS-HD, core plus extension substreams
+ 'dtsl', // DTS-HD Lossless, no core
+ 'dtse', // DTS Express
+] as const;
+export type DtsFourCc = typeof DTS_FOURCCS[number];
+
// Target data rates of the ProRes profiles at 1920x1080 ~30fps, as published by Apple
const PRORES_PROFILE_TARGET_BITRATES: { fourCc: ProresFourCc; bitrate: number; alpha: boolean }[] = [
{ fourCc: 'apco', bitrate: 45_000_000, alpha: false }, // 422 Proxy
@@ -595,6 +604,8 @@ export const buildAudioCodecString = (codec: AudioCodec, numberOfChannels: numbe
return 'ac-3';
} else if (codec === 'eac3') {
return 'ec-3';
+ } else if (codec === 'dts') {
+ return 'dtsc';
} else if ((PCM_AUDIO_CODECS as readonly string[]).includes(codec)) {
return codec;
}
@@ -611,8 +622,9 @@ export const extractAudioCodecString = (trackInfo: {
codec: AudioCodec | null;
codecDescription: Uint8Array | null;
aacCodecInfo: AacCodecInfo | null;
+ dtsFormat: DtsFourCc | null;
}) => {
- const { codec, codecDescription, aacCodecInfo } = trackInfo;
+ const { codec, codecDescription, aacCodecInfo, dtsFormat } = trackInfo;
if (codec === 'aac') {
if (!aacCodecInfo) {
@@ -644,6 +656,8 @@ export const extractAudioCodecString = (trackInfo: {
return 'ac-3';
} else if (codec === 'eac3') {
return 'ec-3';
+ } else if (codec === 'dts') {
+ return dtsFormat ?? 'dtsc';
} else if (codec && (PCM_AUDIO_CODECS as readonly string[]).includes(codec)) {
return codec;
}
@@ -756,6 +770,8 @@ export const inferCodecFromCodecString = (codecString: string): MediaCodec | nul
return 'ac3';
} else if (codecString === 'ec-3' || codecString === 'eac3') {
return 'eac3';
+ } else if ((DTS_FOURCCS as readonly string[]).includes(codecString)) {
+ return 'dts';
} else if (codecString === 'ulaw') {
return 'ulaw';
} else if (codecString === 'alaw') {
@@ -998,7 +1014,7 @@ export const validateVideoChunkMetadata = (
};
const VALID_AUDIO_CODEC_STRING_PREFIXES = [
- 'mp4a', 'mp3', 'opus', 'vorbis', 'flac', 'ulaw', 'alaw', 'pcm', 'ac-3', 'ec-3',
+ 'mp4a', 'mp3', 'opus', 'vorbis', 'flac', 'ulaw', 'alaw', 'pcm', 'ac-3', 'ec-3', 'dts',
];
export const validateAudioChunkMetadata = (
@@ -1132,6 +1148,15 @@ export const validateAudioChunkMetadata = (
if (metadata.decoderConfig.codec !== 'ec-3') {
throw new TypeError('Audio chunk metadata decoder configuration codec string for EC-3 must be "ec-3".');
}
+ } else if (metadata.decoderConfig.codec.startsWith('dts')) {
+ // DTS-specific validation
+
+ if (!(DTS_FOURCCS as readonly string[]).includes(metadata.decoderConfig.codec)) {
+ throw new TypeError(
+ 'Audio chunk metadata decoder configuration codec string for DTS must be one of the following'
+ + ` four-character codes: ${DTS_FOURCCS.join(', ')}.`,
+ );
+ }
} else if (
metadata.decoderConfig.codec.startsWith('pcm')
|| metadata.decoderConfig.codec.startsWith('ulaw')
diff --git a/src/encode.ts b/src/encode.ts
index 656122d..a30fd9f 100644
--- a/src/encode.ts
+++ b/src/encode.ts
@@ -858,6 +858,7 @@ export class Quality {
vorbis: 64000, // 64kbps base for Vorbis
ac3: 384000, // 384kbps base for AC-3
eac3: 192000, // 192kbps base for E-AC-3
+ dts: 768000, // 768kbps base for DTS
};
const baseBitrate = baseRates[codec as keyof typeof baseRates];
@@ -1071,7 +1072,7 @@ export const canEncodeVideo = async (
}
validateVideoEncodingAdditionalOptions(codec, restOptions);
- const resolvedQuality = resolveQuality(quality, bitrate) ?? new Quality({ bitrate: 1e6 });
+ const resolvedQuality = resolveQuality(quality, bitrate) ?? new Quality('medium');
let candidates: VideoEncoderConfigCandidate[];
try {
@@ -1222,7 +1223,7 @@ export const canEncodeAudio = async (
}
validateAudioEncodingAdditionalOptions(codec, restOptions);
- const resolvedQuality = resolveQuality(quality, bitrate) ?? new Quality({ bitrate: 128e3 });
+ const resolvedQuality = resolveQuality(quality, bitrate) ?? new Quality('medium');
const encoderConfig = buildAudioEncoderConfig({
codec,
diff --git a/src/isobmff/isobmff-boxes.ts b/src/isobmff/isobmff-boxes.ts
index 3867fc4..ca3ba8b 100644
--- a/src/isobmff/isobmff-boxes.ts
+++ b/src/isobmff/isobmff-boxes.ts
@@ -43,7 +43,13 @@ import {
IsobmffVideoTrackData,
Sample,
} from './isobmff-muxer';
-import { parseAc3SyncFrame, parseEac3SyncFrame, parseOpusIdentificationHeader } from '../codec-data';
+import {
+ buildDtsSpecificBox,
+ parseAc3SyncFrame,
+ parseDtsFrame,
+ parseEac3SyncFrame,
+ parseOpusIdentificationHeader,
+} from '../codec-data';
import { MetadataTags, RichImageData } from '../metadata';
import { Bitstream } from '../../shared/bitstream';
@@ -690,7 +696,11 @@ export const stsd = (trackData: IsobmffTrackData) => {
trackData,
);
} else if (trackData.type === 'audio') {
- const boxName = audioCodecToBoxName(trackData.track.source._codec, trackData.muxer.isQuickTime);
+ const boxName = audioCodecToBoxName(
+ trackData.track.source._codec,
+ trackData.info.decoderConfig.codec,
+ trackData.muxer.isQuickTime,
+ );
assert(boxName);
sampleDescription = soundSampleDescription(
@@ -968,7 +978,11 @@ export const wave = (trackData: IsobmffAudioTrackData) => {
export const frma = (trackData: IsobmffAudioTrackData) => {
return box('frma', [
- ascii(audioCodecToBoxName(trackData.track.source._codec, trackData.muxer.isQuickTime)),
+ ascii(audioCodecToBoxName(
+ trackData.track.source._codec,
+ trackData.info.decoderConfig.codec,
+ trackData.muxer.isQuickTime,
+ )),
]);
};
@@ -1123,6 +1137,21 @@ const dec3 = (trackData: IsobmffAudioTrackData) => {
return box('dec3', [...bytes]);
};
+/** DTSSpecificBox */
+const ddts = (trackData: IsobmffAudioTrackData) => {
+ assert(trackData.info.primingPacket);
+
+ const frameInfo = parseDtsFrame(trackData.info.primingPacket.data);
+ if (!frameInfo) {
+ throw new Error(
+ 'Couldn\'t extract DTS frame info from the audio packet. '
+ + 'Ensure the packets contain valid DTS frames as specified in ETSI TS 102 114.',
+ );
+ }
+
+ return box('ddts', [...buildDtsSpecificBox(frameInfo)]);
+};
+
export const subtitleSampleDescription = (
compressionType: string,
trackData: IsobmffSubtitleTrackData,
@@ -1816,7 +1845,7 @@ const VIDEO_CODEC_TO_CONFIGURATION_BOX: Record<
prores: null,
};
-const audioCodecToBoxName = (codec: AudioCodec, isQuickTime: boolean): string => {
+const audioCodecToBoxName = (codec: AudioCodec, fullCodecString: string, isQuickTime: boolean): string => {
switch (codec) {
case 'aac': return 'mp4a';
case 'mp3': return 'mp4a';
@@ -1829,6 +1858,7 @@ const audioCodecToBoxName = (codec: AudioCodec, isQuickTime: boolean): string =>
case 'pcm-s8': return 'sowt';
case 'ac3': return 'ac-3';
case 'eac3': return 'ec-3';
+ case 'dts': return fullCodecString;
}
// Logic diverges here
@@ -1870,6 +1900,7 @@ const audioCodecToConfigurationBox = (codec: AudioCodec, isQuickTime: boolean) =
case 'flac': return dfLa;
case 'ac3': return dac3;
case 'eac3': return dec3;
+ case 'dts': return ddts;
}
// Logic diverges here
diff --git a/src/isobmff/isobmff-demuxer.ts b/src/isobmff/isobmff-demuxer.ts
index 98ab435..8419780 100644
--- a/src/isobmff/isobmff-demuxer.ts
+++ b/src/isobmff/isobmff-demuxer.ts
@@ -11,6 +11,8 @@ import { parseAacAudioSpecificConfig } from '../../shared/aac-misc';
import {
AacCodecInfo,
AudioCodec,
+ DTS_FOURCCS,
+ DtsFourCc,
extractAudioCodecString,
extractVideoCodecString,
MediaCodec,
@@ -33,6 +35,9 @@ import {
parseEac3Config,
getEac3SampleRate,
getEac3ChannelCount,
+ extractDtsFourCcFromPacket,
+ parseDtsSpecificBox,
+ DTS_SPECIFIC_BOX_SIZE,
AC3_ACMOD_CHANNEL_COUNTS,
} from '../codec-data';
import { Demuxer } from '../demuxer';
@@ -159,6 +164,7 @@ type InternalTrack = {
codec: AudioCodec | null;
codecDescription: Uint8Array | null;
aacCodecInfo: AacCodecInfo | null;
+ dtsFormat: DtsFourCc | null;
pcmLittleEndian: boolean;
pcmSampleSize: number | null;
};
@@ -1034,6 +1040,7 @@ export class IsobmffDemuxer extends Demuxer {
codec: null,
codecDescription: null,
aacCodecInfo: null,
+ dtsFormat: null,
pcmLittleEndian: false,
pcmSampleSize: null,
};
@@ -1185,6 +1192,9 @@ export class IsobmffDemuxer extends Demuxer {
track.info.codec = 'ac3';
} else if (codecName === 'ec-3') {
track.info.codec = 'eac3';
+ } else if ((DTS_FOURCCS as readonly string[]).includes(codecName!)) {
+ track.info.codec = 'dts';
+ track.info.dtsFormat = codecName as DtsFourCc;
} else if (codecName === 'twos') {
if (sampleSize === 8) {
track.info.codec = 'pcm-s8';
@@ -1564,6 +1574,8 @@ export class IsobmffDemuxer extends Demuxer {
track.info.codec = 'mp3';
} else if (objectTypeIndication === 0xdd) {
track.info.codec = 'vorbis'; // "nonstandard, gpac uses it" - FFmpeg
+ } else if (objectTypeIndication === 0xa9) {
+ track.info.codec = 'dts';
} else {
Logging._warn(
`Unsupported audio codec (objectTypeIndication ${objectTypeIndication}) - discarding track.`,
@@ -1763,6 +1775,28 @@ export class IsobmffDemuxer extends Demuxer {
track.info.numberOfChannels = getEac3ChannelCount(config);
}; break;
+ case 'ddts': { // DTSSpecificBox
+ const track = this.currentTrack;
+ if (!track) {
+ break;
+ }
+ assert(track.info?.type === 'audio');
+
+ const bytes = readBytes(slice, Math.min(boxInfo.contentSize, DTS_SPECIFIC_BOX_SIZE));
+ const config = parseDtsSpecificBox(bytes);
+
+ if (!config) {
+ Logging._warn('Invalid ddts box contents, ignoring.');
+ break;
+ }
+
+ track.info.sampleRate = config.sampleRate;
+
+ if (config.numberOfChannels !== null) {
+ track.info.numberOfChannels = config.numberOfChannels;
+ }
+ }; break;
+
case 'stts': {
const track = this.currentTrack;
if (!track) {
@@ -3404,7 +3438,7 @@ class IsobmffVideoTrackBacking extends IsobmffTrackBacking implements InputVideo
class IsobmffAudioTrackBacking extends IsobmffTrackBacking implements InputAudioTrackBacking {
override internalTrack: InternalAudioTrack;
- decoderConfig: AudioDecoderConfig | null = null;
+ decoderConfigPromise: Promise | null = null;
constructor(internalTrack: InternalAudioTrack) {
super(internalTrack);
@@ -3432,12 +3466,20 @@ class IsobmffAudioTrackBacking extends IsobmffTrackBacking implements InputAudio
return null;
}
- return this.decoderConfig ??= {
- codec: extractAudioCodecString(this.internalTrack.info),
- numberOfChannels: this.internalTrack.info.numberOfChannels,
- sampleRate: this.internalTrack.info.sampleRate,
- description: this.internalTrack.info.codecDescription ?? undefined,
- };
+ return this.decoderConfigPromise ??= (async (): Promise => {
+ if (this.internalTrack.info.codec === 'dts' && !this.internalTrack.info.dtsFormat) {
+ // Gotta check the packet to determine the DTS variant
+ const firstPacket = await this.getFirstPacket({});
+ this.internalTrack.info.dtsFormat = firstPacket && extractDtsFourCcFromPacket(firstPacket.data);
+ }
+
+ return {
+ codec: extractAudioCodecString(this.internalTrack.info),
+ numberOfChannels: this.internalTrack.info.numberOfChannels,
+ sampleRate: this.internalTrack.info.sampleRate,
+ description: this.internalTrack.info.codecDescription ?? undefined,
+ };
+ })();
}
}
diff --git a/src/isobmff/isobmff-muxer.ts b/src/isobmff/isobmff-muxer.ts
index 06b5f15..4d6c8c5 100644
--- a/src/isobmff/isobmff-muxer.ts
+++ b/src/isobmff/isobmff-muxer.ts
@@ -531,10 +531,14 @@ export class IsobmffMuxer extends Muxer {
requiresAdtsStripping = true;
}
- if (track.source._codec === 'ac3' || track.source._codec === 'eac3') {
- if (!packet) {
+ if (!packet) {
+ if (track.source._codec === 'ac3' || track.source._codec === 'eac3') {
throw new Error('AC-3/E-AC-3 require a priming packet.');
}
+
+ if (track.source._codec === 'dts') {
+ throw new Error('DTS requires a priming packet.');
+ }
}
const newTrackData: IsobmffAudioTrackData = {
diff --git a/src/matroska/ebml.ts b/src/matroska/ebml.ts
index 08a07c7..6cc5a88 100644
--- a/src/matroska/ebml.ts
+++ b/src/matroska/ebml.ts
@@ -750,6 +750,7 @@ export const CODEC_STRING_MAP: Partial> = {
'flac': 'A_FLAC',
'ac3': 'A_AC3',
'eac3': 'A_EAC3',
+ 'dts': 'A_DTS',
'pcm-u8': 'A_PCM/INT/LIT',
'pcm-s16': 'A_PCM/INT/LIT',
'pcm-s16be': 'A_PCM/INT/BIG',
diff --git a/src/matroska/matroska-demuxer.ts b/src/matroska/matroska-demuxer.ts
index 26d538b..9fbbc3f 100644
--- a/src/matroska/matroska-demuxer.ts
+++ b/src/matroska/matroska-demuxer.ts
@@ -9,6 +9,7 @@
import { TrackType } from '../output';
import {
extractAv1CodecInfoFromPacket,
+ extractDtsFourCcFromPacket,
extractAvcDecoderConfigurationRecord,
extractHevcDecoderConfigurationRecord,
extractVp9CodecInfoFromPacket,
@@ -16,6 +17,7 @@ import {
import {
AacCodecInfo,
AudioCodec,
+ DtsFourCc,
extractAudioCodecString,
extractVideoCodecString,
MediaCodec,
@@ -229,6 +231,7 @@ type InternalTrack = {
codec: AudioCodec | null;
codecDescription: Uint8Array | null;
aacCodecInfo: AacCodecInfo | null;
+ dtsFormat: DtsFourCc | null;
};
};
type InternalVideoTrack = InternalTrack & { info: { type: 'video' } };
@@ -1127,6 +1130,14 @@ export class MatroskaDemuxer extends Demuxer {
} else if (codecIdWithoutSuffix === CODEC_STRING_MAP.eac3) {
this.currentTrack.info.codec = 'eac3';
this.currentTrack.info.codecDescription = this.currentTrack.codecPrivate;
+ } else if (codecIdWithoutSuffix === CODEC_STRING_MAP.dts) {
+ this.currentTrack.info.codec = 'dts';
+
+ if (this.currentTrack.codecId === 'A_DTS/EXPRESS') {
+ this.currentTrack.info.dtsFormat = 'dtse';
+ } else if (this.currentTrack.codecId === 'A_DTS/LOSSLESS') {
+ this.currentTrack.info.dtsFormat = 'dtsl';
+ }
} else if (this.currentTrack.codecId === 'A_PCM/INT/LIT') {
if (this.currentTrack.info.bitDepth === 8) {
this.currentTrack.info.codec = 'pcm-u8';
@@ -1200,6 +1211,7 @@ export class MatroskaDemuxer extends Demuxer {
codec: null,
codecDescription: null,
aacCodecInfo: null,
+ dtsFormat: null,
};
}
}; break;
@@ -2556,7 +2568,7 @@ class MatroskaVideoTrackBacking extends MatroskaTrackBacking implements InputVid
class MatroskaAudioTrackBacking extends MatroskaTrackBacking implements InputAudioTrackBacking {
override internalTrack: InternalAudioTrack;
- decoderConfig: AudioDecoderConfig | null = null;
+ decoderConfigPromise: Promise | null = null;
constructor(internalTrack: InternalAudioTrack) {
super(internalTrack);
@@ -2584,15 +2596,24 @@ class MatroskaAudioTrackBacking extends MatroskaTrackBacking implements InputAud
return null;
}
- return this.decoderConfig ??= {
- codec: extractAudioCodecString({
- codec: this.internalTrack.info.codec,
- codecDescription: this.internalTrack.info.codecDescription,
- aacCodecInfo: this.internalTrack.info.aacCodecInfo,
- }),
- numberOfChannels: this.internalTrack.info.numberOfChannels,
- sampleRate: this.internalTrack.info.sampleRate,
- description: this.internalTrack.info.codecDescription ?? undefined,
- };
+ return this.decoderConfigPromise ??= (async (): Promise => {
+ if (this.internalTrack.info.codec === 'dts' && !this.internalTrack.info.dtsFormat) {
+ // Gotta check the packet to determine the DTS variant
+ const firstPacket = await this.getFirstPacket({});
+ this.internalTrack.info.dtsFormat = firstPacket && extractDtsFourCcFromPacket(firstPacket.data);
+ }
+
+ return {
+ codec: extractAudioCodecString({
+ codec: this.internalTrack.info.codec,
+ codecDescription: this.internalTrack.info.codecDescription,
+ aacCodecInfo: this.internalTrack.info.aacCodecInfo,
+ dtsFormat: this.internalTrack.info.dtsFormat,
+ }),
+ numberOfChannels: this.internalTrack.info.numberOfChannels,
+ sampleRate: this.internalTrack.info.sampleRate,
+ description: this.internalTrack.info.codecDescription ?? undefined,
+ };
+ })();
}
}
diff --git a/src/matroska/matroska-muxer.ts b/src/matroska/matroska-muxer.ts
index 41b0525..7763df3 100644
--- a/src/matroska/matroska-muxer.ts
+++ b/src/matroska/matroska-muxer.ts
@@ -310,9 +310,18 @@ export class MatroskaMuxer extends Muxer {
this.tracksElement = tracksElement;
for (const trackData of this.trackDatas) {
- const codecId = CODEC_STRING_MAP[trackData.track.source._codec];
+ let codecId = CODEC_STRING_MAP[trackData.track.source._codec];
assert(codecId);
+ if (trackData.type === 'audio' && trackData.track.source._codec === 'dts') {
+ // We can further refine the Codec ID
+ if (trackData.info.decoderConfig.codec === 'dtse') {
+ codecId = 'A_DTS/EXPRESS';
+ } else if (trackData.info.decoderConfig.codec === 'dtsl') {
+ codecId = 'A_DTS/LOSSLESS';
+ }
+ }
+
let seekPreRollNs = 0;
if (trackData.type === 'audio' && trackData.track.source._codec === 'opus') {
seekPreRollNs = 1e6 * 80; // In "Matroska ticks" (nanoseconds)
diff --git a/src/misc.ts b/src/misc.ts
index bd6979d..60fea06 100644
--- a/src/misc.ts
+++ b/src/misc.ts
@@ -472,6 +472,17 @@ export const ilog = (x: number) => {
return ret;
};
+export const popcount = (value: number) => {
+ let count = 0;
+
+ while (value !== 0) {
+ value &= value - 1;
+ count++;
+ }
+
+ return count;
+};
+
const ISO_639_2_REGEX = /^[a-z]{3}$/;
export const isIso639Dash2LanguageCode = (x: string) => {
return ISO_639_2_REGEX.test(x);
diff --git a/src/mpeg-ts/mpeg-ts-demuxer.ts b/src/mpeg-ts/mpeg-ts-demuxer.ts
index f82a09c..54635cd 100644
--- a/src/mpeg-ts/mpeg-ts-demuxer.ts
+++ b/src/mpeg-ts/mpeg-ts-demuxer.ts
@@ -13,6 +13,7 @@ import { aacChannelMap, aacFrequencyTable } from '../../shared/aac-misc';
import {
AacCodecInfo,
AudioCodec,
+ DtsFourCc,
extractAudioCodecString,
extractVideoCodecString,
MediaCodec,
@@ -38,6 +39,12 @@ import {
AC3_FRAME_SIZES,
extractNalUnitTypeForAvc,
extractNalUnitTypeForHevc,
+ parseDtsFrame,
+ parseDtsCoreFrameHeader,
+ parseDtsExssHeader,
+ DTS_CORE_FRAME_HEADER_SIZE,
+ DTS_EXSS_HEADER_PREFIX_SIZE,
+ DTS_EXSS_MAX_HEADER_SIZE,
} from '../codec-data';
import { Demuxer } from '../demuxer';
import { Input } from '../input';
@@ -82,6 +89,22 @@ import { Bitstream } from '../../shared/bitstream';
const MISSING_PTS_ERROR_MESSAGE = 'PES packet is missing PTS where it was expected. PES packets without PTS are not'
+ ' currently supported. If you think this file should be supported, please report it.';
+const REGISTRATION_DESCRIPTOR_TAG = 0x05;
+
+// The 'HDMV' and 'HDPR' format identifiers, which mark a program as Blu-ray-derived
+const HDMV_FORMAT_IDENTIFIER = 0x48444d56;
+const HDPR_FORMAT_IDENTIFIER = 0x48445052;
+
+// 'DTS1', 'DTS2' and 'DTS3' all share this prefix
+const DTS_FORMAT_IDENTIFIER_PREFIX = 0x44545300;
+
+// Stream types that only mean DTS within a Blu-ray-derived program
+const BLU_RAY_DTS_STREAM_TYPES = new Set([
+ MpegTsStreamType.BLU_RAY_DTS_HD,
+ MpegTsStreamType.BLU_RAY_DTS_HD_MASTER,
+ MpegTsStreamType.BLU_RAY_DTS_EXPRESS_SECONDARY,
+]);
+
type ElementaryStream = {
demuxer: MpegTsDemuxer;
pid: number;
@@ -110,6 +133,7 @@ type ElementaryStream = {
codec: AudioCodec;
decoderConfig: AudioDecoderConfig | null;
aacCodecInfo: AacCodecInfo | null;
+ dtsFormat: DtsFourCc | null;
numberOfChannels: number;
sampleRate: number;
};
@@ -294,7 +318,27 @@ export class MpegTsDemuxer extends Demuxer {
// "The remaining 10 bits specify the number of bytes of the descriptors immediately following the
// program_info_length field"
const programInfoLength = bitstream.readBits(10);
- bitstream.skipBits(8 * programInfoLength);
+
+ // A few stream types only mean what Blu-ray says they mean, and the program's registration
+ // descriptor is what tells us we're looking at a Blu-ray-derived stream.
+ const programInfoEndPos = bitstream.pos + 8 * programInfoLength;
+ let isBluRayProgram = false;
+
+ while (bitstream.pos < programInfoEndPos) {
+ const descriptorTag = bitstream.readBits(8);
+ const descriptorLength = bitstream.readBits(8);
+ const descriptorEndPos = bitstream.pos + 8 * descriptorLength;
+
+ if (descriptorTag === REGISTRATION_DESCRIPTOR_TAG && descriptorLength >= 4) {
+ const formatIdentifier = bitstream.readBits(32);
+ isBluRayProgram ||= formatIdentifier === HDMV_FORMAT_IDENTIFIER
+ || formatIdentifier === HDPR_FORMAT_IDENTIFIER;
+ }
+
+ bitstream.pos = descriptorEndPos;
+ }
+
+ bitstream.pos = programInfoEndPos;
while (8 * (sectionLength + BYTES_BEFORE_SECTION_LENGTH) - bitstream.pos > BITS_IN_CRC_32) {
const streamType = bitstream.readBits(8);
@@ -304,24 +348,40 @@ export class MpegTsDemuxer extends Demuxer {
bitstream.skipBits(6);
const esInfoLength = bitstream.readBits(10);
- // Check ES descriptors to detect AC-3/E-AC-3 in System B
+ // Check ES descriptors to detect AC-3/E-AC-3/DTS in System B
const esInfoEndPos = bitstream.pos + 8 * esInfoLength;
let hasAc3Descriptor = false;
let hasEac3Descriptor = false;
+ let hasDtsDescriptor = false;
while (bitstream.pos < esInfoEndPos) {
const descriptorTag = bitstream.readBits(8);
const descriptorLength = bitstream.readBits(8);
+ const descriptorEndPos = bitstream.pos + 8 * descriptorLength;
+
if (descriptorTag === 0x6a) {
hasAc3Descriptor = true;
} else if (descriptorTag === 0x7a || descriptorTag === 0xcc) {
hasEac3Descriptor = true;
+ } else if (descriptorTag === 0x7b) {
+ hasDtsDescriptor = true;
+ } else if (descriptorTag === REGISTRATION_DESCRIPTOR_TAG && descriptorLength >= 4) {
+ // DTS uses 'DTS1', 'DTS2' and 'DTS3' to also signal the stream's frame size,
+ // which we work out from the bitstream anyway
+ const formatIdentifier = bitstream.readBits(32);
+ hasDtsDescriptor ||= (formatIdentifier & 0xffffff00) === DTS_FORMAT_IDENTIFIER_PREFIX;
}
- bitstream.skipBits(8 * descriptorLength);
+
+ bitstream.pos = descriptorEndPos;
}
let info: ElementaryStream['info'] | null = null;
- switch (streamType) {
+ // Blu-ray has its own stream types for the DTS extensions
+ const effectiveStreamType = isBluRayProgram && BLU_RAY_DTS_STREAM_TYPES.has(streamType)
+ ? MpegTsStreamType.DTS
+ : streamType;
+
+ switch (effectiveStreamType) {
case MpegTsStreamType.AVC:
case MpegTsStreamType.HEVC: {
const codec = streamType === MpegTsStreamType.AVC ? 'avc' : 'hevc';
@@ -350,21 +410,23 @@ export class MpegTsDemuxer extends Demuxer {
case MpegTsStreamType.MP3_MPEG2:
case MpegTsStreamType.AAC:
case MpegTsStreamType.AC3_SYSTEM_A:
- case MpegTsStreamType.EAC3_SYSTEM_A: {
+ case MpegTsStreamType.EAC3_SYSTEM_A:
+ case MpegTsStreamType.DTS:
+ case MpegTsStreamType.DTS_ATSC: {
let codec: AudioCodec;
if (
- streamType === MpegTsStreamType.MP3_MPEG1
- || streamType === MpegTsStreamType.MP3_MPEG2
+ effectiveStreamType === MpegTsStreamType.MP3_MPEG1
+ || effectiveStreamType === MpegTsStreamType.MP3_MPEG2
) {
codec = 'mp3';
- } else if (streamType === MpegTsStreamType.AAC) {
+ } else if (effectiveStreamType === MpegTsStreamType.AAC) {
codec = 'aac';
- } else if (streamType === MpegTsStreamType.AC3_SYSTEM_A) {
+ } else if (effectiveStreamType === MpegTsStreamType.AC3_SYSTEM_A) {
codec = 'ac3';
- } else if (streamType === MpegTsStreamType.EAC3_SYSTEM_A) {
+ } else if (effectiveStreamType === MpegTsStreamType.EAC3_SYSTEM_A) {
codec = 'eac3';
} else {
- throw new Error('Unreachable.');
+ codec = 'dts';
}
info = {
@@ -372,6 +434,7 @@ export class MpegTsDemuxer extends Demuxer {
codec,
decoderConfig: null,
aacCodecInfo: null,
+ dtsFormat: null,
numberOfChannels: -1,
sampleRate: -1,
};
@@ -384,6 +447,7 @@ export class MpegTsDemuxer extends Demuxer {
codec: 'eac3',
decoderConfig: null,
aacCodecInfo: null,
+ dtsFormat: null,
numberOfChannels: -1,
sampleRate: -1,
};
@@ -393,6 +457,17 @@ export class MpegTsDemuxer extends Demuxer {
codec: 'ac3',
decoderConfig: null,
aacCodecInfo: null,
+ dtsFormat: null,
+ numberOfChannels: -1,
+ sampleRate: -1,
+ };
+ } else if (hasDtsDescriptor) {
+ info = {
+ type: 'audio',
+ codec: 'dts',
+ decoderConfig: null,
+ aacCodecInfo: null,
+ dtsFormat: null,
numberOfChannels: -1,
sampleRate: -1,
};
@@ -678,6 +753,22 @@ export class MpegTsDemuxer extends Demuxer {
elementaryStream.info.numberOfChannels = getEac3ChannelCount(frameInfo);
elementaryStream.info.sampleRate = sampleRate;
+ } else if (elementaryStream.info.codec === 'dts') {
+ const frameInfo = parseDtsFrame(context.suppliedPacket.data);
+ if (!frameInfo) {
+ throw new Error(
+ 'Invalid DTS audio stream; could not read frame header from first packet.',
+ );
+ }
+
+ elementaryStream.info.numberOfChannels = frameInfo.numberOfChannels;
+ elementaryStream.info.sampleRate = frameInfo.sampleRate;
+
+ if (frameInfo.core) {
+ // Telling the two extension-only variants apart would need us to work out
+ // whether the asset holds XLL or LBR data, so we leave those unlabeled
+ elementaryStream.info.dtsFormat = frameInfo.hasExtensions ? 'dtsh' : 'dtsc';
+ }
} else {
throw new Error('Unhandled.');
}
@@ -687,6 +778,7 @@ export class MpegTsDemuxer extends Demuxer {
codec: elementaryStream.info.codec,
codecDescription: null,
aacCodecInfo: elementaryStream.info.aacCodecInfo,
+ dtsFormat: elementaryStream.info.dtsFormat,
}),
numberOfChannels: elementaryStream.info.numberOfChannels,
sampleRate: elementaryStream.info.sampleRate,
@@ -2315,6 +2407,89 @@ class PacketReadingContext {
samplesPerFrame * TIMESCALE / elementaryStream.info.sampleRate,
);
return this.supplyPacket(remaining, duration);
+ } else if (codec === 'dts') {
+ if (byte !== 0x7f && byte !== 0x64) {
+ continue;
+ }
+
+ this.skip(-1);
+ const possibleSyncPos = this.currentPos;
+
+ let remaining = this.ensureBuffered(DTS_CORE_FRAME_HEADER_SIZE);
+ if (remaining instanceof Promise) remaining = await remaining;
+
+ if (remaining < DTS_CORE_FRAME_HEADER_SIZE) {
+ return;
+ }
+
+ const headerBytes = this.readBytes(DTS_CORE_FRAME_HEADER_SIZE);
+ const core = parseDtsCoreFrameHeader(headerBytes);
+ let leadingExss = core ? null : parseDtsExssHeader(headerBytes);
+
+ if (!core && !leadingExss) {
+ this.seekTo(possibleSyncPos + 1);
+ continue;
+ }
+
+ if (leadingExss && !leadingExss.asset) {
+ // The static fields and the asset descriptor reach past the bytes we read for the
+ // core header, so take another look with the substream's whole header available
+ this.seekTo(possibleSyncPos);
+
+ const headerBound = Math.min(leadingExss.frameSize, DTS_EXSS_MAX_HEADER_SIZE);
+ let remaining = this.ensureBuffered(headerBound);
+ if (remaining instanceof Promise) remaining = await remaining;
+
+ leadingExss = parseDtsExssHeader(this.readBytes(remaining)) ?? leadingExss;
+ }
+
+ let frameSize = core ? core.frameSize : leadingExss!.frameSize;
+
+ // Extension-only streams put exactly one substream in each frame, so it's only a core
+ // frame that needs us to go looking for the extensions riding along with it. The core is
+ // padded out to a 4-byte boundary before the first of them starts.
+ if (core) {
+ let nextSubstreamPos = Math.ceil(core.frameSize / 4) * 4;
+
+ while (true) {
+ this.seekTo(possibleSyncPos);
+
+ const neededBytes = nextSubstreamPos + DTS_EXSS_HEADER_PREFIX_SIZE;
+ let remaining = this.ensureBuffered(neededBytes);
+ if (remaining instanceof Promise) remaining = await remaining;
+
+ if (remaining < neededBytes) {
+ break;
+ }
+
+ this.seekTo(possibleSyncPos + nextSubstreamPos);
+
+ const exss = parseDtsExssHeader(this.readBytes(DTS_EXSS_HEADER_PREFIX_SIZE));
+ if (!exss) {
+ break;
+ }
+
+ nextSubstreamPos += exss.frameSize;
+ frameSize = nextSubstreamPos;
+ }
+ }
+
+ // Only the substream leading the frame declares how many samples the frame holds
+ const sampleCount = core?.sampleCount ?? leadingExss!.asset?.sampleCount;
+ if (sampleCount === undefined) {
+ this.seekTo(possibleSyncPos + 1);
+ continue;
+ }
+
+ this.seekTo(possibleSyncPos);
+
+ remaining = this.ensureBuffered(frameSize);
+ if (remaining instanceof Promise) remaining = await remaining;
+
+ const duration = Math.round(
+ sampleCount * TIMESCALE / elementaryStream.info.sampleRate,
+ );
+ return this.supplyPacket(remaining, duration);
} else {
throw new Error('Unhandled.');
}
diff --git a/src/mpeg-ts/mpeg-ts-misc.ts b/src/mpeg-ts/mpeg-ts-misc.ts
index d19d062..23b2d4d 100644
--- a/src/mpeg-ts/mpeg-ts-misc.ts
+++ b/src/mpeg-ts/mpeg-ts-misc.ts
@@ -15,6 +15,11 @@ export const enum MpegTsStreamType {
AAC = 0x0f,
AC3_SYSTEM_A = 0x81,
EAC3_SYSTEM_A = 0x87,
+ DTS = 0x82,
+ DTS_ATSC = 0x8a,
+ BLU_RAY_DTS_HD = 0x85,
+ BLU_RAY_DTS_HD_MASTER = 0x86,
+ BLU_RAY_DTS_EXPRESS_SECONDARY = 0xa2,
PRIVATE_DATA = 0x06,
AVC = 0x1b,
HEVC = 0x24,
diff --git a/src/mpeg-ts/mpeg-ts-muxer.ts b/src/mpeg-ts/mpeg-ts-muxer.ts
index d48f99e..8320a7f 100644
--- a/src/mpeg-ts/mpeg-ts-muxer.ts
+++ b/src/mpeg-ts/mpeg-ts-muxer.ts
@@ -161,7 +161,7 @@ export class MpegTsMuxer extends Muxer {
assert(meta?.decoderConfig);
const codec = track.source._codec;
- assert(codec === 'aac' || codec === 'mp3' || codec === 'ac3' || codec === 'eac3');
+ assert(codec === 'aac' || codec === 'mp3' || codec === 'ac3' || codec === 'eac3' || codec === 'dts');
let streamType: MpegTsStreamType;
let streamId: number;
@@ -186,6 +186,11 @@ export class MpegTsMuxer extends Muxer {
streamType = MpegTsStreamType.EAC3_SYSTEM_A;
streamId = 0xbd;
}; break;
+
+ case 'dts': {
+ streamType = MpegTsStreamType.DTS;
+ streamId = 0xbd;
+ }; break;
}
const pid = FIRST_TRACK_PID + this.trackDatas.length;
@@ -414,7 +419,7 @@ export class MpegTsMuxer extends Muxer {
): Uint8Array {
const codec = (trackData.track as OutputAudioTrack).source._codec;
- if (codec === 'mp3' || codec === 'ac3' || codec === 'eac3') {
+ if (codec === 'mp3' || codec === 'ac3' || codec === 'eac3' || codec === 'dts') {
// We're good
return packet.data;
}
diff --git a/src/output-format.ts b/src/output-format.ts
index 9098282..96186a9 100644
--- a/src/output-format.ts
+++ b/src/output-format.ts
@@ -1153,7 +1153,7 @@ export class MpegTsOutputFormat extends OutputFormat {
getSupportedCodecs(): MediaCodec[] {
return [
...VIDEO_CODECS.filter(codec => ['avc', 'hevc'].includes(codec)),
- ...AUDIO_CODECS.filter(codec => ['aac', 'mp3', 'ac3', 'eac3'].includes(codec)),
+ ...AUDIO_CODECS.filter(codec => ['aac', 'mp3', 'ac3', 'eac3', 'dts'].includes(codec)),
];
}
diff --git a/test/node/dts.test.ts b/test/node/dts.test.ts
new file mode 100644
index 0000000..6ddfa76
--- /dev/null
+++ b/test/node/dts.test.ts
@@ -0,0 +1,171 @@
+import { expect, test } from 'vitest';
+import path from 'node:path';
+import { Input } from '../../src/input.js';
+import { BufferSource, FilePathSource } from '../../src/source.js';
+import { ALL_FORMATS } from '../../src/input-format.js';
+import { Output } from '../../src/output.js';
+import { MkvOutputFormat, Mp4OutputFormat, MpegTsOutputFormat, OutputFormat } from '../../src/output-format.js';
+import { BufferTarget } from '../../src/target.js';
+import { Conversion } from '../../src/conversion.js';
+import { EncodedPacketSink } from '../../src/media-sink.js';
+import { EncodedPacket } from '../../src/packet.js';
+import { assert, uint8ArraysAreEqual } from '../../src/misc.js';
+
+const __dirname = new URL('.', import.meta.url).pathname;
+
+const DTSC_FILE = 'toothsome-dts.mp4';
+const ESDS_FILE = 'toothsome-dts-esds.mp4';
+
+const MP4_TIMESTAMP_TOLERANCE = 0;
+const MATROSKA_TIMESTAMP_TOLERANCE = 1 / 1000;
+const MPEG_TS_TIMESTAMP_TOLERANCE = 1 / 90_000;
+
+test('Read from MP4 with a dtsc sample entry', async () => {
+ using input = new Input({
+ source: new FilePathSource(path.join(__dirname, '..', 'public', DTSC_FILE)),
+ formats: ALL_FORMATS,
+ });
+
+ const track = await input.getPrimaryAudioTrack();
+ assert(track);
+
+ const decoderConfig = await track.getDecoderConfig();
+ assert(decoderConfig);
+
+ expect(await track.getCodec()).toBe('dts');
+ expect(decoderConfig.codec).toBe('dtsc');
+ expect(decoderConfig.description).toBeUndefined();
+
+ // This file declares 48000 in its sample entry, which the ddts box then corrects to the real rate
+ expect(await track.getSampleRate()).toBe(24000);
+ expect(await track.getNumberOfChannels()).toBe(2);
+
+ await expectStreamShape(input);
+});
+
+test('Read from MP4 with an esds sample entry', async () => {
+ using input = new Input({
+ source: new FilePathSource(path.join(__dirname, '..', 'public', ESDS_FILE)),
+ formats: ALL_FORMATS,
+ });
+
+ const track = await input.getPrimaryAudioTrack();
+ assert(track);
+
+ const decoderConfig = await track.getDecoderConfig();
+ assert(decoderConfig);
+
+ expect(await track.getCodec()).toBe('dts');
+ expect(decoderConfig.codec).toBe('dtsc');
+ expect(decoderConfig.description).toBeUndefined();
+
+ expect(await track.getSampleRate()).toBe(24000);
+ expect(await track.getNumberOfChannels()).toBe(2);
+
+ await expectStreamShape(input);
+});
+
+test('Transmux dtsc MP4 into MP4', async () => {
+ await expectTransmuxToPreservePackets(DTSC_FILE, new Mp4OutputFormat(), MP4_TIMESTAMP_TOLERANCE);
+});
+
+test('Transmux dtsc MP4 into Matroska', async () => {
+ await expectTransmuxToPreservePackets(DTSC_FILE, new MkvOutputFormat(), MATROSKA_TIMESTAMP_TOLERANCE);
+});
+
+test('Transmux dtsc MP4 into MPEG-TS', async () => {
+ await expectTransmuxToPreservePackets(DTSC_FILE, new MpegTsOutputFormat(), MPEG_TS_TIMESTAMP_TOLERANCE);
+});
+
+test('Transmux esds MP4 into MP4', async () => {
+ await expectTransmuxToPreservePackets(ESDS_FILE, new Mp4OutputFormat(), MP4_TIMESTAMP_TOLERANCE);
+});
+
+test('Transmux esds MP4 into Matroska', async () => {
+ await expectTransmuxToPreservePackets(ESDS_FILE, new MkvOutputFormat(), MATROSKA_TIMESTAMP_TOLERANCE);
+});
+
+test('Transmux esds MP4 into MPEG-TS', async () => {
+ await expectTransmuxToPreservePackets(ESDS_FILE, new MpegTsOutputFormat(), MPEG_TS_TIMESTAMP_TOLERANCE);
+});
+
+const expectStreamShape = async (input: Input) => {
+ const packets = await readAllPackets(input);
+
+ expect(packets.length).toBe(1805);
+ expect(packets.every(packet => packet.type === 'key')).toBe(true);
+ expect(packets.every(packet => packet.data.byteLength === 512)).toBe(true);
+};
+
+/** Converts the file without re-encoding and checks that every packet comes back out unchanged. */
+const expectTransmuxToPreservePackets = async (
+ fileName: string,
+ outputFormat: OutputFormat,
+ timestampTolerance: number,
+) => {
+ using originalInput = new Input({
+ source: new FilePathSource(path.join(__dirname, '..', 'public', fileName)),
+ formats: ALL_FORMATS,
+ });
+
+ const originalPackets = await readAllPackets(originalInput);
+
+ const output = new Output({
+ format: outputFormat,
+ target: new BufferTarget(),
+ });
+
+ const conversion = await Conversion.init({ input: originalInput, output });
+ await conversion.execute();
+
+ const { buffer } = output.target;
+ assert(buffer);
+
+ using newInput = new Input({
+ source: new BufferSource(buffer),
+ formats: ALL_FORMATS,
+ });
+
+ const newTrack = await newInput.getPrimaryAudioTrack();
+ assert(newTrack);
+
+ const newDecoderConfig = await newTrack.getDecoderConfig();
+ assert(newDecoderConfig);
+
+ expect(await newTrack.getCodec()).toBe('dts');
+ expect(await newTrack.getSampleRate()).toBe(24000);
+ expect(await newTrack.getNumberOfChannels()).toBe(2);
+
+ // Only the MP4 sample entry can carry this, so for the other formats it comes back out of the bitstream
+ expect(newDecoderConfig.codec).toBe('dtsc');
+
+ const newPackets = await readAllPackets(newInput);
+ expectPacketsToMatch(newPackets, originalPackets, timestampTolerance);
+};
+
+const expectPacketsToMatch = (actual: EncodedPacket[], expected: EncodedPacket[], timestampTolerance: number) => {
+ expect(actual.length).toBe(expected.length);
+
+ for (let i = 0; i < expected.length; i++) {
+ const actualPacket = actual[i]!;
+ const expectedPacket = expected[i]!;
+
+ expect(actualPacket.type).toBe(expectedPacket.type);
+ expect(uint8ArraysAreEqual(actualPacket.data, expectedPacket.data)).toBe(true);
+ expect(Math.abs(actualPacket.timestamp - expectedPacket.timestamp)).toBeLessThanOrEqual(timestampTolerance);
+ }
+};
+
+const readAllPackets = async (input: Input) => {
+ const track = await input.getPrimaryAudioTrack();
+ assert(track);
+
+ const sink = new EncodedPacketSink(track);
+ const packets: EncodedPacket[] = [];
+
+ for await (const packet of sink.packets()) {
+ packets.push(packet);
+ }
+
+ return packets;
+};
diff --git a/test/node/server-extension.test.ts b/test/node/server-extension.test.ts
index 88033d2..bc28490 100644
--- a/test/node/server-extension.test.ts
+++ b/test/node/server-extension.test.ts
@@ -1400,6 +1400,9 @@ describe('Video', async () => {
});
describe('Audio', async () => {
+ /** A DTS bitrate that clears the encoder's per-frame minimum at the 48 kHz stereo the tests here use. */
+ const DTS_BITRATE = 768000;
+
test('Decoder lifecycle', async () => {
using input = new Input({
source: new FilePathSource('./test/public/trim-buck-bunny-ffmpeg.ts'),
@@ -1726,6 +1729,25 @@ describe('Audio', async () => {
});
});
+ test('DTS encode & decode', async () => {
+ await encodeDecodeTest('dts', { bitrate: DTS_BITRATE }, async (packet, meta, i) => {
+ expect(packet.type).toBe('key');
+ expect(packet.duration).toBeCloseTo(512 / 48000);
+
+ if (i === 0) {
+ expect(meta.decoderConfig).toBeDefined();
+ expect(meta.decoderConfig!.codec).toBe('dtsc');
+ expect(meta.decoderConfig!.numberOfChannels).toBe(2);
+ expect(meta.decoderConfig!.sampleRate).toBe(48000);
+ expect(meta.decoderConfig!.description).toBeUndefined();
+ }
+ }, async (sample) => {
+ expect(sample.numberOfChannels).toBe(2);
+ expect(sample.sampleRate).toBe(48000);
+ expect(sample.duration).toBeCloseTo(512 / 48000);
+ });
+ });
+
for (const codec of NON_PCM_AUDIO_CODECS) {
test(`${codec} encode & decode, negative timestamps`, async () => {
await timestampTest(codec, -1);
@@ -1747,7 +1769,10 @@ describe('Audio', async () => {
const testDuration = codec !== 'opus';
const testSampleStart = codec !== 'vorbis';
- await encodeDecodeTest(codec, {}, async (packet, _meta, i) => {
+ // The harness' default bitrate is below what DTS needs to fit its per-channel side info into a frame
+ const extraConfig = codec === 'dts' ? { bitrate: DTS_BITRATE } : {};
+
+ await encodeDecodeTest(codec, extraConfig, async (packet, _meta, i) => {
if (i === 0) {
expect(packet.timestamp).toBe(startTimestamp);
} else if (testDuration) {
diff --git a/test/public/toothsome-dts-esds.mp4 b/test/public/toothsome-dts-esds.mp4
new file mode 100644
index 0000000..ab704ed
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diff --git a/test/public/toothsome-dts.mp4 b/test/public/toothsome-dts.mp4
new file mode 100644
index 0000000..f7e1ade
Binary files /dev/null and b/test/public/toothsome-dts.mp4 differ