| <!DOCTYPE html> |
| <html> |
| <head> |
| <script src="../../resources/testharness.js"></script> |
| <script src="../../resources/testharnessreport.js"></script> |
| </head> |
| <body> |
| <script> |
| // Data offsets for audio-aac.mp4 |
| // - AudioSpecificConfig (description): offset 1757, size 25 bytes |
| // - First AAC sample: offset 44, size 28 bytes |
| // - Sample rate: 48000 Hz |
| // - Channels: 4 (quad) |
| // - First sample timestamp: 0 (in 48000 Hz time base) |
| // - Sample duration: 1024 samples |
| |
| const descriptionOffset = 1757; |
| const descriptionSize = 25; |
| const sampleOffset = 44; |
| const sampleSize = 28; |
| const sampleRate = 48000; |
| const numberOfChannels = 4; |
| const sampleTimestamp = 0; // in 48000 Hz time base |
| const sampleDuration = 1024; // in samples |
| |
| promise_test(async () => { |
| const response = await fetch("./resources/audio-aac.mp4"); |
| const buffer = await response.arrayBuffer(); |
| |
| let decodedFrames = []; |
| let decodeError = null; |
| |
| const decoder = new AudioDecoder({ |
| output(frame) { |
| decodedFrames.push({ |
| timestamp: frame.timestamp, |
| duration: frame.duration, |
| numberOfFrames: frame.numberOfFrames, |
| numberOfChannels: frame.numberOfChannels, |
| sampleRate: frame.sampleRate, |
| format: frame.format |
| }); |
| frame.close(); |
| }, |
| error(e) { |
| decodeError = e; |
| } |
| }); |
| |
| // Configure the decoder with AAC-LC codec and the AudioSpecificConfig from the MP4 file |
| const description = new Uint8Array(buffer, descriptionOffset, descriptionSize); |
| decoder.configure({ |
| codec: 'mp4a.40.2', // AAC-LC |
| sampleRate: sampleRate, |
| numberOfChannels: numberOfChannels, |
| description: description |
| }); |
| |
| // Create an EncodedAudioChunk from the first AAC sample |
| const sampleData = new Uint8Array(buffer, sampleOffset, sampleSize); |
| // Convert timestamp from 48000 Hz time base to microseconds |
| const timestampMicroseconds = Math.round((sampleTimestamp / sampleRate) * 1000000); |
| const durationMicroseconds = Math.round((sampleDuration / sampleRate) * 1000000); |
| |
| const chunk = new EncodedAudioChunk({ |
| type: 'key', |
| timestamp: timestampMicroseconds, |
| duration: durationMicroseconds, |
| data: sampleData |
| }); |
| |
| decoder.decode(chunk); |
| await decoder.flush(); |
| |
| assert_equals(decodeError, null, "No decode error should occur"); |
| assert_equals(decodedFrames.length, 1, "Should have decoded exactly one frame"); |
| |
| const frame = decodedFrames[0]; |
| assert_equals(frame.numberOfChannels, numberOfChannels, "Decoded frame should have correct number of channels"); |
| assert_equals(frame.sampleRate, sampleRate, "Decoded frame should have correct sample rate"); |
| assert_equals(frame.numberOfFrames, sampleDuration, "Decoded frame should have correct number of samples"); |
| assert_equals(frame.timestamp, timestampMicroseconds, "Decoded frame should have correct timestamp"); |
| |
| decoder.close(); |
| }, "Decode first AAC sample from MP4 file with extended AudioSpecificConfig"); |
| </script> |
| </body> |
| </html> |
