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Don't use WavHeader.averageBytesPerSecond

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It's unreliable for at least one IMA ADPCM file I've found.
Calculating the blockIndex to seek to using exact properties
also seems more robust.

Note this doesn't change anything for the existing PCM test,
since averageBytesPerSecond is set correctly. It does make
a difference for an upcoming IMA ADPCM test though.

PiperOrigin-RevId: 287814947
This commit is contained in:
olly 2020-01-02 11:37:03 +00:00 committed by Oliver Woodman
parent 3cf88bb48b
commit 1edcc6c4f7
2 changed files with 5 additions and 7 deletions
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2
library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavExtractor.java
View File

@ -203,7 +203,7 @@ public final class WavExtractor implements Extractor {
/* id= */ null,
MimeTypes.AUDIO_RAW,
/* codecs= */ null,
/* bitrate= */ header.averageBytesPerSecond * 8,
/* bitrate= */ header.frameRateHz * bytesPerFrame * 8,
targetSampleSize,
header.numChannels,
header.frameRateHz,

10
library/core/src/main/java/com/google/android/exoplayer2/extractor/wav/WavSeekMap.java
View File

@ -49,20 +49,18 @@ import com.google.android.exoplayer2.util.Util;
@Override
public SeekPoints getSeekPoints(long timeUs) {
// Calculate the expected number of bytes of sample data corresponding to the requested time.
long positionOffset = (timeUs * wavHeader.averageBytesPerSecond) / C.MICROS_PER_SECOND;
// Calculate the containing block index, constraining to valid indices.
long blockSize = wavHeader.blockSize;
long blockIndex = Util.constrainValue(positionOffset / blockSize, 0, blockCount - 1);
long blockIndex = (timeUs * wavHeader.frameRateHz) / (C.MICROS_PER_SECOND * framesPerBlock);
blockIndex = Util.constrainValue(blockIndex, 0, blockCount - 1);
long seekPosition = firstBlockPosition + (blockIndex * blockSize);
long seekPosition = firstBlockPosition + (blockIndex * wavHeader.blockSize);
long seekTimeUs = blockIndexToTimeUs(blockIndex);
SeekPoint seekPoint = new SeekPoint(seekTimeUs, seekPosition);
if (seekTimeUs >= timeUs || blockIndex == blockCount - 1) {
return new SeekPoints(seekPoint);
} else {
long secondBlockIndex = blockIndex + 1;
long secondSeekPosition = firstBlockPosition + (secondBlockIndex * blockSize);
long secondSeekPosition = firstBlockPosition + (secondBlockIndex * wavHeader.blockSize);
long secondSeekTimeUs = blockIndexToTimeUs(secondBlockIndex);
SeekPoint secondSeekPoint = new SeekPoint(secondSeekTimeUs, secondSeekPosition);
return new SeekPoints(seekPoint, secondSeekPoint);