FFMPEG Plugin: Implement audio input buffer padding.
- Padding is required by FFMPEG for correct operation of all audio decoders. FFMPEG performs some speed optimizations under the hood that may lead to reading over the end of the chunk buffer wouldn't there have been padding applied. - Resolve TODOs by unifying fVideoChunkBuffer and fChunkBuffer back into fChunkBuffer because audio path is responsible for freeing fChunkBuffer now. Resolved TODOs apply to the replacing fVideoChunkBuffer variable by fChunkBuffer, rename some methods by removing the "Video" part, collapse two methods into one (_LoadNextChunkIfNeededAndAssignStartTime()). No functional change intended. - Enhance "logging stream to file" functionality to write to distinct logging files for audio and video. Before this commit one could only log video streams. But with unifying the _LoadNextChunkIfNeededAndAssignStartTime() audio streams gained the logging functionality for free. But now audio and video streams would be written in the same log file when watching a media file containing both audio and video. This is prevented by the distinct logging mentioned above. - Update documentation accordingly.
This commit is contained in:
Colin Günther
parent
3c68ae7c58
commit
f7f6702203
@ -39,7 +39,11 @@
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//#define LOG_STREAM_TO_FILE
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#ifdef LOG_STREAM_TO_FILE
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# include <File.h>
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static BFile sStreamLogFile("/boot/home/Desktop/AVCodecDebugStream.raw",
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static BFile sAudioStreamLogFile(
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"/boot/home/Desktop/AVCodecDebugAudioStream.raw",
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B_CREATE_FILE | B_ERASE_FILE | B_WRITE_ONLY);
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static BFile sVideoStreamLogFile(
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"/boot/home/Desktop/AVCodecDebugVideoStream.raw",
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B_CREATE_FILE | B_ERASE_FILE | B_WRITE_ONLY);
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static int sDumpedPackets = 0;
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#endif
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@ -111,7 +115,6 @@ AVCodecDecoder::AVCodecDecoder()
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fOutputFrameSize(0),
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fChunkBuffer(NULL),
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fVideoChunkBuffer(NULL),
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fChunkBufferSize(0),
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fAudioDecodeError(false),
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@ -145,9 +148,7 @@ AVCodecDecoder::~AVCodecDecoder()
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if (fCodecInitDone)
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avcodec_close(fContext);
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free(fVideoChunkBuffer);
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// TODO: Replace with fChunkBuffer, once audio path is
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// responsible for freeing the chunk buffer, too.
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free(fChunkBuffer);
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free(fDecodedData);
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av_free(fPostProcessedDecodedPicture);
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@ -270,10 +271,7 @@ AVCodecDecoder::SeekedTo(int64 frame, bigtime_t time)
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}
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// Flush internal buffers as well.
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free(fVideoChunkBuffer);
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// TODO: Replace with fChunkBuffer, once audio path is
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// responsible for freeing the chunk buffer, too.
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fVideoChunkBuffer = NULL;
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free(fChunkBuffer);
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fChunkBuffer = NULL;
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fChunkBufferSize = 0;
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fDecodedDataBufferOffset = 0;
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@ -360,6 +358,7 @@ AVCodecDecoder::_NegotiateAudioOutputFormat(media_format* inOutFormat)
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return B_ERROR;
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}
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free(fChunkBuffer);
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fChunkBuffer = NULL;
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fChunkBufferSize = 0;
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fAudioDecodeError = false;
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@ -472,6 +471,10 @@ AVCodecDecoder::_NegotiateVideoOutputFormat(media_format* inOutFormat)
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fFormatConversionFunc = 0;
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#endif
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free(fChunkBuffer);
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fChunkBuffer = NULL;
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fChunkBufferSize = 0;
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_ResetTempPacket();
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status_t statusOfDecodingFirstFrame = _DecodeNextVideoFrame();
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@ -926,7 +929,7 @@ AVCodecDecoder::_DecodeNextAudioFrameChunk()
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while(fDecodedDataBufferSize == 0) {
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status_t loadingChunkStatus
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= _LoadNextAudioChunkIfNeededAndAssignStartTime();
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= _LoadNextChunkIfNeededAndAssignStartTime();
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if (loadingChunkStatus != B_OK)
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return loadingChunkStatus;
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@ -939,8 +942,7 @@ AVCodecDecoder::_DecodeNextAudioFrameChunk()
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if (!fAudioDecodeError) {
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// Report failure if not done already
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int32 chunkBufferOffset = fTempPacket.data
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- static_cast<uint8_t*>(const_cast<void*>(fChunkBuffer));
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int32 chunkBufferOffset = fTempPacket.data - fChunkBuffer;
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printf("########### audio decode error, "
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"fTempPacket.size %d, fChunkBuffer data offset %ld\n",
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fTempPacket.size, chunkBufferOffset);
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@ -958,69 +960,6 @@ AVCodecDecoder::_DecodeNextAudioFrameChunk()
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}
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/*! \brief Loads the next audio chunk into fChunkBuffer and assigns it
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(including the start time) to fTempPacket accordingly only if
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fTempPacket is empty.
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\returns B_OK
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1. meaning: Next audio chunk is loaded.
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2. meaning: No need to load and assign anything. Proceed as usual.
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\returns B_LAST_BUFFER_ERROR No more audio chunks available.
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fChunkBuffer and fTempPacket are left untouched.
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\returns Other errors Caller should bail out because fChunkBuffer and
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fTempPacket are in unknown states. Normal operation cannot be
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guaranteed.
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*/
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status_t
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AVCodecDecoder::_LoadNextAudioChunkIfNeededAndAssignStartTime()
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{
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// TODO: Collapse _LoadNextAudioChunkIfNeededAndAssignStartTime() and
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// _LoadNextVideoChunkIfNeededAndAssignStartTime() into one method called
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// _LoadNextChunkIfNeededAndAssignStartTime() once the following conditions
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// are met:
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// 1. There is no longer a distinction between fVideoChunkBuffer and
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// fChunkBuffer.
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// 2. _LoadNextAudioChunkIfNeededAndAssignStartTime() adds Padding to
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// the chunk buffer, too, like it is done in
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// _LoadNextVideoChunkIfNeededAndAssignStartTime() at the moment.
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if (fTempPacket.size > 0)
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return B_OK;
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const void* chunkBuffer = NULL;
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size_t chunkBufferSize = 0;
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// In the case that GetNextChunk() returns an error fChunkBufferSize
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// should be left untouched.
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media_header chunkMediaHeader;
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status_t getNextChunkStatus = GetNextChunk(&chunkBuffer, &chunkBufferSize,
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&chunkMediaHeader);
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if (getNextChunkStatus != B_OK)
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return getNextChunkStatus;
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fChunkBuffer = chunkBuffer;
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fChunkBufferSize = chunkBufferSize;
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fTempPacket.data
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= static_cast<uint8_t*>(const_cast<void*>(fChunkBuffer));
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fTempPacket.size = fChunkBufferSize;
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fTempPacket.dts = chunkMediaHeader.start_time;
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// Let FFMPEG handle the correct relationship between start_time and
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// decoded audio frames. By doing so we are merely following the way it
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// is done for the video path.
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// see _LoadNextVideoChunkIfNeededAndAssignStartTime()
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//
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// FIXME: Research how to establish a meaningful relationship
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// between start_time and decoded audio frame when the received chunk
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// buffer contains partial video frames. Maybe some data formats
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// contain time stamps (ake pts / dts fields) that can be evaluated by
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// FFMPEG. But as long as I don't have such audio data to test it, it
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// makes no sense to implement it.
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return B_OK;
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}
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/*! \brief Tries to decode at least one audio frame and store it in the
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fDecodedDataBuffer.
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@ -1185,11 +1124,9 @@ AVCodecDecoder::_DecodeNextVideoFrame()
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while (true) {
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status_t loadingChunkStatus
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= _LoadNextVideoChunkIfNeededAndAssignStartTime();
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= _LoadNextChunkIfNeededAndAssignStartTime();
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if (loadingChunkStatus == B_LAST_BUFFER_ERROR)
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return _FlushOneVideoFrameFromDecoderBuffer();
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if (loadingChunkStatus != B_OK) {
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TRACE("AVCodecDecoder::_DecodeNextVideoFrame(): error from "
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"GetNextChunk(): %s\n", strerror(loadingChunkStatus));
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@ -1301,25 +1238,21 @@ AVCodecDecoder::_ApplyEssentialVideoContainerPropertiesToContext()
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}
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/*! \brief Loads the next video chunk into fVideoChunkBuffer and assigns it
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(including the start time) to fTempPacket accordingly only if
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fTempPacket is empty.
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/*! \brief Loads the next chunk into fChunkBuffer and assigns it (including
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the start time) to fTempPacket but only if fTempPacket is empty.
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\returns B_OK
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1. meaning: Next video chunk is loaded.
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1. meaning: Next chunk is loaded.
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2. meaning: No need to load and assign anything. Proceed as usual.
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\returns B_LAST_BUFFER_ERROR No more video chunks available.
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fVideoChunkBuffer and fTempPacket are left untouched.
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\returns Other errors Caller should bail out because fVideoChunkBuffer and
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\returns B_LAST_BUFFER_ERROR No more chunks available. fChunkBuffer and
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fTempPacket are left untouched.
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\returns Other errors Caller should bail out because fChunkBuffer and
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fTempPacket are in unknown states. Normal operation cannot be
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guaranteed.
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*/
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status_t
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AVCodecDecoder::_LoadNextVideoChunkIfNeededAndAssignStartTime()
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AVCodecDecoder::_LoadNextChunkIfNeededAndAssignStartTime()
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{
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// TODO: Rename fVideoChunkBuffer to fChunkBuffer, once the audio path is
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// responsible for releasing the chunk buffer, too.
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if (fTempPacket.size > 0)
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return B_OK;
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@ -1335,25 +1268,25 @@ AVCodecDecoder::_LoadNextVideoChunkIfNeededAndAssignStartTime()
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return getNextChunkStatus;
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status_t chunkBufferPaddingStatus
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= _CopyChunkToVideoChunkBufferAndAddPadding(chunkBuffer,
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chunkBufferSize);
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= _CopyChunkToChunkBufferAndAddPadding(chunkBuffer, chunkBufferSize);
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if (chunkBufferPaddingStatus != B_OK)
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return chunkBufferPaddingStatus;
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fTempPacket.data = fVideoChunkBuffer;
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fTempPacket.data = fChunkBuffer;
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fTempPacket.size = fChunkBufferSize;
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fTempPacket.dts = chunkMediaHeader.start_time;
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// Let FFMPEG handle the correct relationship between start_time and
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// decoded video frame. By doing so we are simply copying the way how
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// it is implemented in ffplay.c
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// decoded a/v frame. By doing so we are simply copying the way how it
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// is implemented in ffplay.c for video frames (for audio frames it
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// works, too, but isn't used by ffplay.c).
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// \see http://git.videolan.org/?p=ffmpeg.git;a=blob;f=ffplay.c;h=09623db374e5289ed20b7cc28c262c4375a8b2e4;hb=9153b33a742c4e2a85ff6230aea0e75f5a8b26c2#l1502
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//
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// FIXME: Research how to establish a meaningful relationship
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// between start_time and decoded video frame when the received chunk
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// buffer contains partial video frames. Maybe some data formats
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// contain time stamps (ake pts / dts fields) that can be evaluated by
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// FFMPEG. But as long as I don't have such video data to test it, it
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// makes no sense to implement it.
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// FIXME: Research how to establish a meaningful relationship between
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// start_time and decoded a/v frame when the received chunk buffer
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// contains partial a/v frames. Maybe some data formats do contain time
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// stamps (ake pts / dts fields) that can be evaluated by FFMPEG. But
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// as long as I don't have such video data to test it, it makes no
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// sense trying to implement it.
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//
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// FIXME: Implement tracking start_time of video frames originating in
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// data chunks that encode more than one video frame at a time. In that
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@ -1363,19 +1296,20 @@ AVCodecDecoder::_LoadNextVideoChunkIfNeededAndAssignStartTime()
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// to implement it.
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#ifdef LOG_STREAM_TO_FILE
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BFile* logFile = fIsAudio ? &sAudioStreamLogFile : &sVideoStreamLogFile;
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if (sDumpedPackets < 100) {
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sStreamLogFile.Write(chunkBuffer, fChunkBufferSize);
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logFile->Write(chunkBuffer, fChunkBufferSize);
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printf("wrote %ld bytes\n", fChunkBufferSize);
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sDumpedPackets++;
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} else if (sDumpedPackets == 100)
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sStreamLogFile.Unset();
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logFile->Unset();
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#endif
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return B_OK;
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}
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/*! \brief Copies a chunk into fVideoChunkBuffer and adds a "safety net" of
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/*! \brief Copies a chunk into fChunkBuffer and adds a "safety net" of
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additional memory as required by FFMPEG for input buffers to video
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decoders.
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@ -1385,11 +1319,11 @@ AVCodecDecoder::_LoadNextVideoChunkIfNeededAndAssignStartTime()
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The additional memory has a size of FF_INPUT_BUFFER_PADDING_SIZE as defined
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in avcodec.h.
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Ownership of fVideoChunkBuffer memory is with the class so it needs to be
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freed at the right times (on destruction, on seeking).
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Ownership of fChunkBuffer memory is with the class so it needs to be freed
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at the right times (on destruction, on seeking).
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Also update fChunkBufferSize to reflect the size of the contained video
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data (leaving out the padding).
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Also update fChunkBufferSize to reflect the size of the contained data
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(leaving out the padding).
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\param chunk The chunk to copy.
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\param chunkSize Size of the chunk in bytes
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@ -1397,25 +1331,22 @@ AVCodecDecoder::_LoadNextVideoChunkIfNeededAndAssignStartTime()
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\returns B_OK Padding was successful. You are responsible for releasing the
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allocated memory. fChunkBufferSize is set to chunkSize.
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\returns B_NO_MEMORY Padding failed.
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fVideoChunkBuffer is set to NULL making it safe to call free() on it.
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fChunkBufferSize is set to 0 to reflect the size of fVideoChunkBuffer.
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fChunkBuffer is set to NULL making it safe to call free() on it.
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fChunkBufferSize is set to 0 to reflect the size of fChunkBuffer.
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*/
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status_t
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AVCodecDecoder::_CopyChunkToVideoChunkBufferAndAddPadding(const void* chunk,
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AVCodecDecoder::_CopyChunkToChunkBufferAndAddPadding(const void* chunk,
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size_t chunkSize)
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{
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// TODO: Rename fVideoChunkBuffer to fChunkBuffer, once the audio path is
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// responsible for releasing the chunk buffer, too.
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fVideoChunkBuffer = static_cast<uint8_t*>(realloc(fVideoChunkBuffer,
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fChunkBuffer = static_cast<uint8_t*>(realloc(fChunkBuffer,
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chunkSize + FF_INPUT_BUFFER_PADDING_SIZE));
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if (fVideoChunkBuffer == NULL) {
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if (fChunkBuffer == NULL) {
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fChunkBufferSize = 0;
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return B_NO_MEMORY;
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}
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memcpy(fVideoChunkBuffer, chunk, chunkSize);
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memset(fVideoChunkBuffer + chunkSize, 0, FF_INPUT_BUFFER_PADDING_SIZE);
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memcpy(fChunkBuffer, chunk, chunkSize);
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memset(fChunkBuffer + chunkSize, 0, FF_INPUT_BUFFER_PADDING_SIZE);
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// Establish safety net, by zero'ing the padding area.
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fChunkBufferSize = chunkSize;
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@ -67,21 +67,14 @@ private:
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void _CheckAndFixConditionsThatHintAtBrokenAudioCodeBelow();
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void _MoveAudioFramesToRawDecodedAudioAndUpdateStartTimes();
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status_t _DecodeNextAudioFrameChunk();
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status_t _LoadNextAudioChunkIfNeededAndAssignStartTime();
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status_t _DecodeSomeAudioFramesIntoEmptyDecodedDataBuffer();
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void _UpdateMediaHeaderForAudioFrame();
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status_t _DecodeNextVideoFrame();
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void _ApplyEssentialVideoContainerPropertiesToContext();
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status_t _LoadNextVideoChunkIfNeededAndAssignStartTime();
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// TODO: Remove the "Video" word once
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// the audio path is responsible for
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// freeing the chunk buffer, too.
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status_t _CopyChunkToVideoChunkBufferAndAddPadding(
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const void* chunk, size_t chunkSize);
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// TODO: Remove the "Video" word once
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// the audio path is responsible for
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// freeing the chunk buffer, too.
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status_t _LoadNextChunkIfNeededAndAssignStartTime();
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status_t _CopyChunkToChunkBufferAndAddPadding(const void* chunk,
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size_t chunkSize);
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void _HandleNewVideoFrameAndUpdateSystemState();
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status_t _FlushOneVideoFrameFromDecoderBuffer();
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void _UpdateMediaHeaderForVideoFrame();
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@ -121,12 +114,7 @@ private:
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int fOutputFrameSize;
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// sample size * channel count
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const void* fChunkBuffer;
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uint8_t* fVideoChunkBuffer;
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// TODO: Remove and use fChunkBuffer again
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// (with type uint8_t*) once the audio path
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// is responsible for freeing the chunk
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// buffer, too.
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uint8_t* fChunkBuffer;
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size_t fChunkBufferSize;
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bool fAudioDecodeError;
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