Commit 58bb97a5 authored by Paul Adenot's avatar Paul Adenot
Browse files

Bug 1844741 - Consistently use remaining padding when trimming mp3. r=alwu, a=dsmith 

Creating the file was made in the following way:
- Create a VBR file
- Modify the padding field so that it spans multiple packets (greater than 1152
frames in this case)
- Copy and paste the last mp3 packet (starting with 0xfffd) multiple times so
that more packets are found after having trimmed the last packet (marked as
EOS).

Differential Revision: https://phabricator.services.mozilla.com/D184213
parent 24e00c6f

dom/media/mp3/MP3Demuxer.cpp

+2 −1
Changes for dom/media/mp3/MP3Demuxer.cpp: 2 added lines, 1 removed line.
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ UniquePtr<TrackInfo> MP3TrackDemuxer::GetInfo() const { return mInfo->Clone(); } 


RefPtr<MP3TrackDemuxer::SeekPromise> MP3TrackDemuxer::Seek(

    const TimeUnit& aTime) {

  mRemainingEncoderPadding = AssertedCast<int32_t>(mEncoderPadding);

  // Efficiently seek to the position.

  FastSeek(aTime);

  // Correct seek position by scanning the next frames.
@@ -735,7 +736,7 @@ already_AddRefed<MediaRawData> MP3TrackDemuxer::GetNextFrame( 
  } else if (frame->mEOS &&

             mRemainingEncoderPadding <=

                 frame->mDuration.ToTicksAtRate(mSamplesPerSecond)) {

    frame->mDuration -= Padding();

    frame->mDuration -= TimeUnit(mRemainingEncoderPadding, mSamplesPerSecond);

    MOZ_ASSERT(frame->mDuration.IsPositiveOrZero());

    MP3LOG("Trimming last packet %s to [%s,%s]", Padding().ToString().get(),

           frame->mTime.ToString().get(), frame->GetEndTime().ToString().get());

dom/media/test/manifest.js

+7 −0
Changes for dom/media/test/manifest.js: 7 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -531,6 +531,13 @@ var gPlayTests = [ 
  // tag. The ID3v1 tags should be at the end of the file, but software usually

  // play it anyway.

  { name: "id3v1afterlongid3v2.mp3", type: "audio/mpeg", duration: 0.5 },

  // An VBR file with a padding value that is greater than an mp3 packet, and

  // also subsequent packets after the theoretical EOF computed from metadata,

  // to test padding trimming edge cases.

  {

    name: "padding-spanning-multiple-packets.mp3",

    type: "audio/mpeg",

  },

  // A truncated VBR MP3 with just enough frames to keep most decoders happy.

  // The Xing header reports the length of the file to be around 10 seconds, but

  // there is really only one second worth of data. We want MP3FrameParser to

dom/media/test/mochitest.ini

+1 −0
Changes for dom/media/test/mochitest.ini: 1 added line, 0 removed lines.
Original line number Diff line number Diff line
@@ -785,6 +785,7 @@ support-files = 
  two-xing-header-no-content-length.mp3^headers^

  single-xing-header-no-content-length.mp3

  single-xing-header-no-content-length.mp3^headers^

  padding-spanning-multiple-packets.mp3



[test_capture_stream_av_sync.html]

skip-if =

dom/media/test/padding-spanning-multiple-packets.mp3

0 → 100644
+115 KiB

File added.

No diff preview for this file type.

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dom/media/test/test_mp3_broadcast.html

+1 −1
Changes for dom/media/test/test_mp3_broadcast.html: 1 added line, 1 removed line.
Original line number Diff line number Diff line
@@ -26,7 +26,7 @@ 
            // This scenario is typical in radio broadcast scenario, when the

            // live-stream has a pre-recorded prelude. The reported duration,

            // after "ended" has been received, is the duration of playback.

            { src: "single-xing-header-no-content-length.mp3", duration: 11.030997 },

            { src: "single-xing-header-no-content-length.mp3", duration: 11.050839},

        ];

        var audio = window.a;

        // Prevent ESLint error about top-level await