Fix file compression example, add processedTime parameter to onProgress for Conversion API

examples/file-compression/file-compression.ts

@@ -62,31 +62,41 @@ const compressFile = async (resource: File | string) => {
 		currentConversion = await Conversion.init({
 			input,
 			output,
-			video: track => ({
+			tracks: 'primary', // Keep only one track per type
+			video: {
 				width: 320, // Height will be deduced automatically to retain aspect ratio
 				bitrate: QUALITY_VERY_LOW,
-				discard: track.number > 1, // Keep only the first video track
+			},
-			}),
+			audio: {
-			audio: track => ({
+				bitrate: QUALITY_VERY_LOW,
-				bitrate: 32e3,
+			},
-				discard: track.number > 1, // Keep only the first audio track
-			}),
 		});
 
+		if (!currentConversion.isValid) {
+			console.info(currentConversion.discardedTracks);
+			throw new Error('Conversion is invalid and cannot be executed; see the console for more.');
+		}
+
 		// Keep track of progress
 		let progress = 0;
-		currentConversion.onProgress = newProgress => progress = newProgress;
+		let processedTime = 0;
+		let startTime: number | null = null;
 
-		const fileDuration = (await input.computeDuration()) - (await input.getFirstTimestamp());
+		currentConversion.onProgress = (newProgress, newProcessedTime) => {
-		const startTime = performance.now();
+			progress = newProgress;
+			processedTime = newProcessedTime;
+			startTime ??= performance.now();
+		};
 
 		const updateProgress = () => {
 			progressBar.style.width = `${progress * 100}%`;
 
-			const now = performance.now();
+			if (startTime !== null) {
-			const elapsedSeconds = (now - startTime) / 1000;
+				const now = performance.now();
-			const factor = fileDuration / (elapsedSeconds / progress);
+				const elapsedSeconds = (now - startTime) / 1000;
-			speedometer.textContent = `Speed: ~${factor.toPrecision(3)}x real time`;
+				const factor = processedTime / elapsedSeconds;
+				speedometer.textContent = `Speed: ~${factor.toPrecision(3)}x real time`;
+			}
 		};
 
 		// Update the progress indicator regularly

src/conversion.ts

@@ -563,13 +563,15 @@ export class Conversion {
 	_canceled = false;
 
 	/**
-	 * A callback that is fired whenever the conversion progresses. Returns a number between 0 and 1, indicating the
+	 * A callback that is fired whenever the conversion progresses. Gets passed as first argument a number between
-	 * completion of the conversion. Note that a progress of 1 doesn't necessarily mean the conversion is complete;
+	 * 0 and 1, indicating the completion of the conversion. Note that a progress of 1 doesn't necessarily mean the
-	 * the conversion is complete once `execute()` resolves.
+	 * conversion is complete; the conversion is complete once `execute()` resolves.
+	 *
+	 * As second argument, this callback receives the input time in seconds that has been processed.
 	 *
 	 * In order for progress to be computed, this property must be set before `execute` is called.
 	 */
-	onProgress?: (progress: number) => unknown = undefined;
+	onProgress?: (progress: number, processedTime: number) => unknown = undefined;
 	/** @internal */
 	_computeProgress = false;
 	/** @internal */
@@ -929,7 +931,11 @@ export class Conversion {
 			}
 
 			if (!this.isValid) {
-				warnElements.push('\n\n' + this._getInvalidityExplanation().join(''));
+				if (warnElements.length > 0) {
+					warnElements.push('\n\n');
+				}
+
+				warnElements.push(this._getInvalidityExplanation().join(''));
 			}
 
 			if (warnElements.length > 0) {
@@ -949,7 +955,7 @@ export class Conversion {
 		} else {
 			const encodabilityIsTheProblem = this.discardedTracks.every(x =>
 				x.reason === 'discarded_by_user' || x.reason === 'no_encodable_target_codec',
-			);
+			) && this.discardedTracks.some(x => x.reason === 'no_encodable_target_codec');
 
 			elements.push(
 				'Due to discarded tracks, this conversion cannot be executed.',
@@ -1054,7 +1060,7 @@ export class Conversion {
 				this._maxTimestamps.set(id, 0);
 			}
 
-			this.onProgress?.(0);
+			this.onProgress?.(0, 0);
 		}
 
 		await this.output.start();
@@ -1078,7 +1084,8 @@ export class Conversion {
 		await this.output.finalize();
 
 		if (this._computeProgress) {
-			this.onProgress?.(1);
+			const minTimestamp = Math.min(...this._maxTimestamps.values());
+			this.onProgress?.(1, minTimestamp);
 		}
 	}
 
@@ -1547,21 +1554,23 @@ export class Conversion {
 			});
 		}
 
-		for (const finalSample of finalSamples) {
+		try {
-			if (this._canceled) {
+			for (const finalSample of finalSamples) {
-				break;
+				if (this._canceled) {
+					break;
+				}
+
+				await source.add(finalSample);
+
+				if (this._synchronizer.shouldWait(outputTrackId, finalSample.timestamp)) {
+					await this._synchronizer.wait(finalSample.timestamp);
+				}
 			}
-
+		} finally {
-			await source.add(finalSample);
+			for (const finalSample of finalSamples) {
-
+				if (finalSample !== sample) {
-			if (this._synchronizer.shouldWait(outputTrackId, finalSample.timestamp)) {
+					finalSample.close();
-				await this._synchronizer.wait(finalSample.timestamp);
+				}
-			}
-		}
-
-		for (const finalSample of finalSamples) {
-			if (finalSample !== sample) {
-				finalSample.close();
 			}
 		}
 	}
@@ -1801,21 +1810,23 @@ export class Conversion {
 			finalSamples = processed;
 		}
 
-		for (const finalSample of finalSamples) {
+		try {
-			if (this._canceled) {
+			for (const finalSample of finalSamples) {
-				break;
+				if (this._canceled) {
+					break;
+				}
+
+				await source.add(finalSample);
+
+				if (this._synchronizer.shouldWait(outputTrackId, finalSample.timestamp)) {
+					await this._synchronizer.wait(finalSample.timestamp);
+				}
 			}
-
+		} finally {
-			await source.add(finalSample);
+			for (const finalSample of finalSamples) {
-
+				if (finalSample !== sample) {
-			if (this._synchronizer.shouldWait(outputTrackId, finalSample.timestamp)) {
+					finalSample.close();
-				await this._synchronizer.wait(finalSample.timestamp);
+				}
-			}
-		}
-
-		for (const finalSample of finalSamples) {
-			if (finalSample !== sample) {
-				finalSample.close();
 			}
 		}
 	}
@@ -1890,7 +1901,7 @@ export class Conversion {
 
 		if (newProgress !== this._lastProgress) {
 			this._lastProgress = newProgress;
-			this.onProgress?.(newProgress);
+			this.onProgress?.(newProgress, minTimestamp);
 		}
 	}
 }