loliball/media3
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

WavExtractor: skip unknown chunks consistently

Browse Source 
#minor-release

PiperOrigin-RevId: 408550935
This commit is contained in:
kimvde 2021-11-09 09:52:45 +00:00 committed by Ian Baker
parent d8b9d378d9
commit f4d85ac247
1 changed files with 33 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
libraries/extractor/src/main/java/androidx/media3/extractor/wav/WavHeaderReader.java
View File

@ -71,14 +71,8 @@ import java.io.IOException;
public static WavFormat readFormat(ExtractorInput input) throws IOException {
// Allocate a scratch buffer large enough to store the format chunk.
ParsableByteArray scratch = new ParsableByteArray(16);
// Skip chunks until we find the format chunk.
ChunkHeader chunkHeader = ChunkHeader.peek(input, scratch);
while (chunkHeader.id != WavUtil.FMT_FOURCC) {
input.skipFully(ChunkHeader.SIZE_IN_BYTES + (int) chunkHeader.size);
chunkHeader = ChunkHeader.peek(input, scratch);
}
ChunkHeader chunkHeader = skipToChunk(/* chunkId= */ WavUtil.FMT_FOURCC, input, scratch);
Assertions.checkState(chunkHeader.size >= 16);
input.peekFully(scratch.getData(), 0, 16);
scratch.setPosition(0);
@ -112,7 +106,8 @@ import java.io.IOException;
/**
* Skips to the data in the given WAV input stream, and returns its bounds. After calling, the
* input stream's position will point to the start of sample data in the WAV. If an exception is
* thrown, the input position will be left pointing to a chunk header.
* thrown, the input position will be left pointing to a chunk header (that may not be the data
* chunk header).
*
* @param input The input stream, whose read position must be pointing to a valid chunk header.
* @return The byte positions at which the data starts (inclusive) and ends (exclusive).
@ -125,17 +120,7 @@ import java.io.IOException;
ParsableByteArray scratch = new ParsableByteArray(ChunkHeader.SIZE_IN_BYTES);
// Skip all chunks until we find the data header.
ChunkHeader chunkHeader = ChunkHeader.peek(input, scratch);
while (chunkHeader.id != WavUtil.DATA_FOURCC) {
Log.w(TAG, "Ignoring unknown WAV chunk: " + chunkHeader.id);
long bytesToSkip = ChunkHeader.SIZE_IN_BYTES + chunkHeader.size;
if (bytesToSkip > Integer.MAX_VALUE) {
throw ParserException.createForUnsupportedContainerFeature(
"Chunk is too large (~2GB+) to skip; id: " + chunkHeader.id);
}
input.skipFully((int) bytesToSkip);
chunkHeader = ChunkHeader.peek(input, scratch);
}
ChunkHeader chunkHeader = skipToChunk(/* chunkId= */ WavUtil.DATA_FOURCC, input, scratch);
// Skip past the "data" header.
input.skipFully(ChunkHeader.SIZE_IN_BYTES);
@ -149,6 +134,35 @@ import java.io.IOException;
return Pair.create(dataStartPosition, dataEndPosition);
}
/**
* Skips to the chunk header corresponding to the {@code chunkId} provided. After calling, the
* input stream's position will point to the chunk header with provided {@code chunkId} and the
* peek position to the chunk body. If an exception is thrown, the input position will be left
* pointing to a chunk header (that may not be the one corresponding to the {@code chunkId}).
*
* @param chunkId The ID of the chunk to skip to.
* @param input The input stream, whose read position must be pointing to a valid chunk header.
* @param scratch A scratch buffer to read the chunk headers.
* @return The {@link ChunkHeader} corresponding to the {@code chunkId} provided.
* @throws ParserException If an error occurs parsing chunks.
* @throws IOException If reading from the input fails.
*/
private static ChunkHeader skipToChunk(
int chunkId, ExtractorInput input, ParsableByteArray scratch) throws IOException {
ChunkHeader chunkHeader = ChunkHeader.peek(input, scratch);
while (chunkHeader.id != chunkId) {
Log.w(TAG, "Ignoring unknown WAV chunk: " + chunkHeader.id);
long bytesToSkip = ChunkHeader.SIZE_IN_BYTES + chunkHeader.size;
if (bytesToSkip > Integer.MAX_VALUE) {
throw ParserException.createForUnsupportedContainerFeature(
"Chunk is too large (~2GB+) to skip; id: " + chunkHeader.id);
}
input.skipFully((int) bytesToSkip);
chunkHeader = ChunkHeader.peek(input, scratch);
}
return chunkHeader;
}
private WavHeaderReader() {
// Prevent instantiation.
}