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Diffstat (limited to 'src/media/UAudioDecoder_FFmpeg.pas')
| -rw-r--r-- | src/media/UAudioDecoder_FFmpeg.pas | 1114 |
1 files changed, 1114 insertions, 0 deletions
diff --git a/src/media/UAudioDecoder_FFmpeg.pas b/src/media/UAudioDecoder_FFmpeg.pas new file mode 100644 index 00000000..d9b4c93c --- /dev/null +++ b/src/media/UAudioDecoder_FFmpeg.pas @@ -0,0 +1,1114 @@ +unit UAudioDecoder_FFmpeg; + +(******************************************************************************* + * + * This unit is primarily based upon - + * http://www.dranger.com/ffmpeg/ffmpegtutorial_all.html + * + * and tutorial03.c + * + * http://www.inb.uni-luebeck.de/~boehme/using_libavcodec.html + * + *******************************************************************************) + +interface + +{$IFDEF FPC} + {$MODE Delphi} +{$ENDIF} + +{$I switches.inc} + +// show FFmpeg specific debug output +{.$DEFINE DebugFFmpegDecode} + +// FFmpeg is very verbose and shows a bunch of errors. +// Those errors (they can be considered as warnings by us) can be ignored +// as they do not give any useful information. +// There is no solution to fix this except for turning them off. +{.$DEFINE EnableFFmpegErrorOutput} + +implementation + +uses + Classes, + SysUtils, + Math, + UMusic, + UIni, + UMain, + avcodec, + avformat, + avutil, + avio, + mathematics, // used for av_rescale_q + rational, + UMediaCore_FFmpeg, + SDL, + ULog, + UCommon, + UConfig; + +const + MAX_AUDIOQ_SIZE = (5 * 16 * 1024); + +const + // TODO: The factor 3/2 might not be necessary as we do not need extra + // space for synchronizing as in the tutorial. + AUDIO_BUFFER_SIZE = (AVCODEC_MAX_AUDIO_FRAME_SIZE * 3) div 2; + +type + TFFmpegDecodeStream = class(TAudioDecodeStream) + private + StateLock: PSDL_Mutex; + + EOFState: boolean; // end-of-stream flag (locked by StateLock) + ErrorState: boolean; // error flag (locked by StateLock) + + QuitRequest: boolean; // (locked by StateLock) + ParserIdleCond: PSDL_Cond; + + // parser pause/resume data + ParserLocked: boolean; + ParserPauseRequestCount: integer; + ParserUnlockedCond: PSDL_Cond; + ParserResumeCond: PSDL_Cond; + + SeekRequest: boolean; // (locked by StateLock) + SeekFlags: integer; // (locked by StateLock) + SeekPos: double; // stream position to seek for (in secs) (locked by StateLock) + SeekFlush: boolean; // true if the buffers should be flushed after seeking (locked by StateLock) + SeekFinishedCond: PSDL_Cond; + + Loop: boolean; // (locked by StateLock) + + ParseThread: PSDL_Thread; + PacketQueue: TPacketQueue; + + FormatInfo: TAudioFormatInfo; + + // FFmpeg specific data + FormatCtx: PAVFormatContext; + CodecCtx: PAVCodecContext; + Codec: PAVCodec; + + AudioStreamIndex: integer; + AudioStream: PAVStream; + AudioStreamPos: double; // stream position in seconds (locked by DecoderLock) + + // decoder pause/resume data + DecoderLocked: boolean; + DecoderPauseRequestCount: integer; + DecoderUnlockedCond: PSDL_Cond; + DecoderResumeCond: PSDL_Cond; + + // state-vars for DecodeFrame (locked by DecoderLock) + AudioPaket: TAVPacket; + AudioPaketData: PChar; + AudioPaketSize: integer; + AudioPaketSilence: integer; // number of bytes of silence to return + + // state-vars for AudioCallback (locked by DecoderLock) + AudioBufferPos: integer; + AudioBufferSize: integer; + AudioBuffer: PChar; + + Filename: string; + + procedure SetPositionIntern(Time: real; Flush: boolean; Blocking: boolean); + procedure SetEOF(State: boolean); {$IFDEF HasInline}inline;{$ENDIF} + procedure SetError(State: boolean); {$IFDEF HasInline}inline;{$ENDIF} + function IsSeeking(): boolean; + function IsQuit(): boolean; + + procedure Reset(); + + procedure Parse(); + function ParseLoop(): boolean; + procedure PauseParser(); + procedure ResumeParser(); + + function DecodeFrame(Buffer: PChar; BufferSize: integer): integer; + procedure FlushCodecBuffers(); + procedure PauseDecoder(); + procedure ResumeDecoder(); + public + constructor Create(); + destructor Destroy(); override; + + function Open(const Filename: string): boolean; + procedure Close(); override; + + function GetLength(): real; override; + function GetAudioFormatInfo(): TAudioFormatInfo; override; + function GetPosition: real; override; + procedure SetPosition(Time: real); override; + function GetLoop(): boolean; override; + procedure SetLoop(Enabled: boolean); override; + function IsEOF(): boolean; override; + function IsError(): boolean; override; + + function ReadData(Buffer: PChar; BufferSize: integer): integer; override; + end; + +type + TAudioDecoder_FFmpeg = class( TInterfacedObject, IAudioDecoder ) + public + function GetName: string; + + function InitializeDecoder(): boolean; + function FinalizeDecoder(): boolean; + function Open(const Filename: string): TAudioDecodeStream; + end; + +var + FFmpegCore: TMediaCore_FFmpeg; + +function ParseThreadMain(Data: Pointer): integer; cdecl; forward; + + +{ TFFmpegDecodeStream } + +constructor TFFmpegDecodeStream.Create(); +begin + inherited Create(); + + StateLock := SDL_CreateMutex(); + ParserUnlockedCond := SDL_CreateCond(); + ParserResumeCond := SDL_CreateCond(); + ParserIdleCond := SDL_CreateCond(); + SeekFinishedCond := SDL_CreateCond(); + DecoderUnlockedCond := SDL_CreateCond(); + DecoderResumeCond := SDL_CreateCond(); + + // according to the documentation of avcodec_decode_audio(2), sample-data + // should be aligned on a 16 byte boundary. Otherwise internal calls + // (e.g. to SSE or Altivec operations) might fail or lack performance on some + // CPUs. Although GetMem() in Delphi and FPC seems to use a 16 byte or higher + // alignment for buffers of this size (alignment depends on the size of the + // requested buffer), we will set the alignment explicitly as the minimum + // alignment used by Delphi and FPC is on an 8 byte boundary. + // + // Note: AudioBuffer was previously defined as a field of type TAudioBuffer + // (array[0..AUDIO_BUFFER_SIZE-1] of byte) and hence statically allocated. + // Fields of records are aligned different to memory allocated with GetMem(), + // aligning depending on the type but will be at least 2 bytes. + // AudioBuffer was not aligned to a 16 byte boundary. The {$ALIGN x} directive + // was not applicable as Delphi in contrast to FPC provides at most 8 byte + // alignment ({$ALIGN 16} is not supported) by this directive. + AudioBuffer := GetAlignedMem(AUDIO_BUFFER_SIZE, 16); + + Reset(); +end; + +procedure TFFmpegDecodeStream.Reset(); +begin + ParseThread := nil; + + EOFState := false; + ErrorState := false; + Loop := false; + QuitRequest := false; + + AudioPaketData := nil; + AudioPaketSize := 0; + AudioPaketSilence := 0; + + AudioBufferPos := 0; + AudioBufferSize := 0; + + ParserLocked := false; + ParserPauseRequestCount := 0; + DecoderLocked := false; + DecoderPauseRequestCount := 0; + + FillChar(AudioPaket, SizeOf(TAVPacket), 0); +end; + +{* + * Frees the decode-stream data. + *} +destructor TFFmpegDecodeStream.Destroy(); +begin + Close(); + + SDL_DestroyMutex(StateLock); + SDL_DestroyCond(ParserUnlockedCond); + SDL_DestroyCond(ParserResumeCond); + SDL_DestroyCond(ParserIdleCond); + SDL_DestroyCond(SeekFinishedCond); + SDL_DestroyCond(DecoderUnlockedCond); + SDL_DestroyCond(DecoderResumeCond); + + FreeAlignedMem(AudioBuffer); + + inherited; +end; + +function TFFmpegDecodeStream.Open(const Filename: string): boolean; +var + SampleFormat: TAudioSampleFormat; + AVResult: integer; +begin + Result := false; + + Close(); + Reset(); + + if (not FileExists(Filename)) then + begin + Log.LogError('Audio-file does not exist: "' + Filename + '"', 'UAudio_FFmpeg'); + Exit; + end; + + Self.Filename := Filename; + + // open audio file + if (av_open_input_file(FormatCtx, PChar(Filename), nil, 0, nil) <> 0) then + begin + Log.LogError('av_open_input_file failed: "' + Filename + '"', 'UAudio_FFmpeg'); + Exit; + end; + + // generate PTS values if they do not exist + FormatCtx^.flags := FormatCtx^.flags or AVFMT_FLAG_GENPTS; + + // retrieve stream information + if (av_find_stream_info(FormatCtx) < 0) then + begin + Log.LogError('av_find_stream_info failed: "' + Filename + '"', 'UAudio_FFmpeg'); + Close(); + Exit; + end; + + // FIXME: hack used by ffplay. Maybe should not use url_feof() to test for the end + FormatCtx^.pb.eof_reached := 0; + + {$IFDEF DebugFFmpegDecode} + dump_format(FormatCtx, 0, pchar(Filename), 0); + {$ENDIF} + + AudioStreamIndex := FFmpegCore.FindAudioStreamIndex(FormatCtx); + if (AudioStreamIndex < 0) then + begin + Log.LogError('FindAudioStreamIndex: No Audio-stream found "' + Filename + '"', 'UAudio_FFmpeg'); + Close(); + Exit; + end; + + //Log.LogStatus('AudioStreamIndex is: '+ inttostr(ffmpegStreamID), 'UAudio_FFmpeg'); + + AudioStream := FormatCtx.streams[AudioStreamIndex]; + CodecCtx := AudioStream^.codec; + + // TODO: should we use this or not? Should we allow 5.1 channel audio? + (* + {$IF LIBAVCODEC_VERSION >= 51042000} + if (CodecCtx^.channels > 0) then + CodecCtx^.request_channels := Min(2, CodecCtx^.channels) + else + CodecCtx^.request_channels := 2; + {$IFEND} + *) + + Codec := avcodec_find_decoder(CodecCtx^.codec_id); + if (Codec = nil) then + begin + Log.LogError('Unsupported codec!', 'UAudio_FFmpeg'); + CodecCtx := nil; + Close(); + Exit; + end; + + // set debug options + CodecCtx^.debug_mv := 0; + CodecCtx^.debug := 0; + + // detect bug-workarounds automatically + CodecCtx^.workaround_bugs := FF_BUG_AUTODETECT; + // error resilience strategy (careful/compliant/agressive/very_aggressive) + //CodecCtx^.error_resilience := FF_ER_CAREFUL; //FF_ER_COMPLIANT; + // allow non spec compliant speedup tricks. + //CodecCtx^.flags2 := CodecCtx^.flags2 or CODEC_FLAG2_FAST; + + // Note: avcodec_open() and avcodec_close() are not thread-safe and will + // fail if called concurrently by different threads. + FFmpegCore.LockAVCodec(); + try + AVResult := avcodec_open(CodecCtx, Codec); + finally + FFmpegCore.UnlockAVCodec(); + end; + if (AVResult < 0) then + begin + Log.LogError('avcodec_open failed!', 'UAudio_FFmpeg'); + Close(); + Exit; + end; + + // now initialize the audio-format + + if (not FFmpegCore.ConvertFFmpegToAudioFormat(CodecCtx^.sample_fmt, SampleFormat)) then + begin + // try standard format + SampleFormat := asfS16; + end; + + FormatInfo := TAudioFormatInfo.Create( + CodecCtx^.channels, + CodecCtx^.sample_rate, + SampleFormat + ); + + + PacketQueue := TPacketQueue.Create(); + + // finally start the decode thread + ParseThread := SDL_CreateThread(@ParseThreadMain, Self); + + Result := true; +end; + +procedure TFFmpegDecodeStream.Close(); +var + ThreadResult: integer; +begin + // wake threads waiting for packet-queue data + // Note: normally, there are no waiting threads. If there were waiting + // ones, they would block the audio-callback thread. + if (assigned(PacketQueue)) then + PacketQueue.Abort(); + + // send quit request (to parse-thread etc) + SDL_mutexP(StateLock); + QuitRequest := true; + SDL_CondBroadcast(ParserIdleCond); + SDL_mutexV(StateLock); + + // abort parse-thread + if (ParseThread <> nil) then + begin + // and wait until it terminates + SDL_WaitThread(ParseThread, ThreadResult); + ParseThread := nil; + end; + + // Close the codec + if (CodecCtx <> nil) then + begin + // avcodec_close() is not thread-safe + FFmpegCore.LockAVCodec(); + try + avcodec_close(CodecCtx); + finally + FFmpegCore.UnlockAVCodec(); + end; + CodecCtx := nil; + end; + + // Close the video file + if (FormatCtx <> nil) then + begin + av_close_input_file(FormatCtx); + FormatCtx := nil; + end; + + PerformOnClose(); + + FreeAndNil(PacketQueue); + FreeAndNil(FormatInfo); +end; + +function TFFmpegDecodeStream.GetLength(): real; +begin + // do not forget to consider the start_time value here + Result := (FormatCtx^.start_time + FormatCtx^.duration) / AV_TIME_BASE; +end; + +function TFFmpegDecodeStream.GetAudioFormatInfo(): TAudioFormatInfo; +begin + Result := FormatInfo; +end; + +function TFFmpegDecodeStream.IsEOF(): boolean; +begin + SDL_mutexP(StateLock); + Result := EOFState; + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.SetEOF(State: boolean); +begin + SDL_mutexP(StateLock); + EOFState := State; + SDL_mutexV(StateLock); +end; + +function TFFmpegDecodeStream.IsError(): boolean; +begin + SDL_mutexP(StateLock); + Result := ErrorState; + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.SetError(State: boolean); +begin + SDL_mutexP(StateLock); + ErrorState := State; + SDL_mutexV(StateLock); +end; + +function TFFmpegDecodeStream.IsSeeking(): boolean; +begin + SDL_mutexP(StateLock); + Result := SeekRequest; + SDL_mutexV(StateLock); +end; + +function TFFmpegDecodeStream.IsQuit(): boolean; +begin + SDL_mutexP(StateLock); + Result := QuitRequest; + SDL_mutexV(StateLock); +end; + +function TFFmpegDecodeStream.GetPosition(): real; +var + BufferSizeSec: double; +begin + PauseDecoder(); + + // ReadData() does not return all of the buffer retrieved by DecodeFrame(). + // Determine the size of the unused part of the decode-buffer. + BufferSizeSec := (AudioBufferSize - AudioBufferPos) / + FormatInfo.BytesPerSec; + + // subtract the size of unused buffer-data from the audio clock. + Result := AudioStreamPos - BufferSizeSec; + + ResumeDecoder(); +end; + +procedure TFFmpegDecodeStream.SetPosition(Time: real); +begin + SetPositionIntern(Time, true, true); +end; + +function TFFmpegDecodeStream.GetLoop(): boolean; +begin + SDL_mutexP(StateLock); + Result := Loop; + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.SetLoop(Enabled: boolean); +begin + SDL_mutexP(StateLock); + Loop := Enabled; + SDL_mutexV(StateLock); +end; + + +(******************************************** + * Parser section + ********************************************) + +procedure TFFmpegDecodeStream.PauseParser(); +begin + if (SDL_ThreadID() = ParseThread.threadid) then + Exit; + + SDL_mutexP(StateLock); + Inc(ParserPauseRequestCount); + while (ParserLocked) do + SDL_CondWait(ParserUnlockedCond, StateLock); + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.ResumeParser(); +begin + if (SDL_ThreadID() = ParseThread.threadid) then + Exit; + + SDL_mutexP(StateLock); + Dec(ParserPauseRequestCount); + SDL_CondSignal(ParserResumeCond); + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.SetPositionIntern(Time: real; Flush: boolean; Blocking: boolean); +begin + // - Pause the parser first to prevent it from putting obsolete packages + // into the queue after the queue was flushed and before seeking is done. + // Otherwise we will hear fragments of old data, if the stream was seeked + // in stopped mode and resumed afterwards (applies to non-blocking mode only). + // - Pause the decoder to avoid race-condition that might occur otherwise. + // - Last lock the state lock because we are manipulating some shared state-vars. + PauseParser(); + PauseDecoder(); + SDL_mutexP(StateLock); + + // configure seek parameters + SeekPos := Time; + SeekFlush := Flush; + SeekFlags := AVSEEK_FLAG_ANY; + SeekRequest := true; + + // Note: the BACKWARD-flag seeks to the first position <= the position + // searched for. Otherwise e.g. position 0 might not be seeked correct. + // For some reason ffmpeg sometimes doesn't use position 0 but the key-frame + // following. In streams with few key-frames (like many flv-files) the next + // key-frame after 0 might be 5secs ahead. + if (Time < AudioStreamPos) then + SeekFlags := SeekFlags or AVSEEK_FLAG_BACKWARD; + + EOFState := false; + ErrorState := false; + + // send a reuse signal in case the parser was stopped (e.g. because of an EOF) + SDL_CondSignal(ParserIdleCond); + + SDL_mutexV(StateLock); + ResumeDecoder(); + ResumeParser(); + + // in blocking mode, wait until seeking is done + if (Blocking) then + begin + SDL_mutexP(StateLock); + while (SeekRequest) do + SDL_CondWait(SeekFinishedCond, StateLock); + SDL_mutexV(StateLock); + end; +end; + +function ParseThreadMain(Data: Pointer): integer; cdecl; +var + Stream: TFFmpegDecodeStream; +begin + Stream := TFFmpegDecodeStream(Data); + if (Stream <> nil) then + Stream.Parse(); + Result := 0; +end; + +procedure TFFmpegDecodeStream.Parse(); +begin + // reuse thread as long as the stream is not terminated + while (ParseLoop()) do + begin + // wait for reuse or destruction of stream + SDL_mutexP(StateLock); + while (not (SeekRequest or QuitRequest)) do + SDL_CondWait(ParserIdleCond, StateLock); + SDL_mutexV(StateLock); + end; +end; + +(** + * Parser main loop. + * Will not return until parsing of the stream is finished. + * Reasons for the parser to return are: + * - the end-of-file is reached + * - an error occured + * - the stream was quited (received a quit-request) + * Returns true if the stream can be resumed or false if the stream has to + * be terminated. + *) +function TFFmpegDecodeStream.ParseLoop(): boolean; +var + Packet: TAVPacket; + StatusPacket: PAVPacket; + SeekTarget: int64; + ByteIOCtx: PByteIOContext; + ErrorCode: integer; + StartSilence: double; // duration of silence at start of stream + StartSilencePtr: PDouble; // pointer for the EMPTY status packet + + // Note: pthreads wakes threads waiting on a mutex in the order of their + // priority and not in FIFO order. SDL does not provide any option to + // control priorities. This might (and already did) starve threads waiting + // on the mutex (e.g. SetPosition) making usdx look like it was froozen. + // Instead of simply locking the critical section we set a ParserLocked flag + // instead and give priority to the threads requesting the parser to pause. + procedure LockParser(); + begin + SDL_mutexP(StateLock); + while (ParserPauseRequestCount > 0) do + SDL_CondWait(ParserResumeCond, StateLock); + ParserLocked := true; + SDL_mutexV(StateLock); + end; + + procedure UnlockParser(); + begin + SDL_mutexP(StateLock); + ParserLocked := false; + SDL_CondBroadcast(ParserUnlockedCond); + SDL_mutexV(StateLock); + end; + +begin + Result := true; + + while (true) do + begin + LockParser(); + try + + if (IsQuit()) then + begin + Result := false; + Exit; + end; + + // handle seek-request (Note: no need to lock SeekRequest here) + if (SeekRequest) then + begin + // first try: seek on the audio stream + SeekTarget := Round(SeekPos / av_q2d(AudioStream^.time_base)); + StartSilence := 0; + if (SeekTarget < AudioStream^.start_time) then + StartSilence := (AudioStream^.start_time - SeekTarget) * av_q2d(AudioStream^.time_base); + ErrorCode := av_seek_frame(FormatCtx, AudioStreamIndex, SeekTarget, SeekFlags); + + if (ErrorCode < 0) then + begin + // second try: seek on the default stream (necessary for flv-videos and some ogg-files) + SeekTarget := Round(SeekPos * AV_TIME_BASE); + StartSilence := 0; + if (SeekTarget < FormatCtx^.start_time) then + StartSilence := (FormatCtx^.start_time - SeekTarget) / AV_TIME_BASE; + ErrorCode := av_seek_frame(FormatCtx, -1, SeekTarget, SeekFlags); + end; + + // pause decoder and lock state (keep the lock-order to avoid deadlocks). + // Note that the decoder does not block in the packet-queue in seeking state, + // so locking the decoder here does not cause a dead-lock. + PauseDecoder(); + SDL_mutexP(StateLock); + try + if (ErrorCode < 0) then + begin + // seeking failed + ErrorState := true; + Log.LogStatus('Seek Error in "'+FormatCtx^.filename+'"', 'UAudioDecoder_FFmpeg'); + end + else + begin + if (SeekFlush) then + begin + // flush queue (we will send a Flush-Packet when seeking is finished) + PacketQueue.Flush(); + + // flush the decode buffers + AudioBufferSize := 0; + AudioBufferPos := 0; + AudioPaketSize := 0; + AudioPaketSilence := 0; + FlushCodecBuffers(); + + // Set preliminary stream position. The position will be set to + // the correct value as soon as the first packet is decoded. + AudioStreamPos := SeekPos; + end + else + begin + // request avcodec buffer flush + PacketQueue.PutStatus(PKT_STATUS_FLAG_FLUSH, nil); + end; + + // fill the gap between position 0 and start_time with silence + // but not if we are in loop mode + if ((StartSilence > 0) and (not Loop)) then + begin + GetMem(StartSilencePtr, SizeOf(StartSilence)); + StartSilencePtr^ := StartSilence; + PacketQueue.PutStatus(PKT_STATUS_FLAG_EMPTY, StartSilencePtr); + end; + end; + + SeekRequest := false; + SDL_CondBroadcast(SeekFinishedCond); + finally + SDL_mutexV(StateLock); + ResumeDecoder(); + end; + end; + + if (PacketQueue.GetSize() > MAX_AUDIOQ_SIZE) then + begin + SDL_Delay(10); + Continue; + end; + + if (av_read_frame(FormatCtx, Packet) < 0) then + begin + // failed to read a frame, check reason + {$IF (LIBAVFORMAT_VERSION_MAJOR >= 52)} + ByteIOCtx := FormatCtx^.pb; + {$ELSE} + ByteIOCtx := @FormatCtx^.pb; + {$IFEND} + + // check for end-of-file (eof is not an error) + if (url_feof(ByteIOCtx) <> 0) then + begin + if (GetLoop()) then + begin + // rewind stream (but do not flush) + SetPositionIntern(0, false, false); + Continue; + end + else + begin + // signal end-of-file + PacketQueue.PutStatus(PKT_STATUS_FLAG_EOF, nil); + Exit; + end; + end; + + // check for errors + if (url_ferror(ByteIOCtx) <> 0) then + begin + // an error occured -> abort and wait for repositioning or termination + PacketQueue.PutStatus(PKT_STATUS_FLAG_ERROR, nil); + Exit; + end; + + // no error -> wait for user input + SDL_Delay(100); + Continue; + end; + + if (Packet.stream_index = AudioStreamIndex) then + PacketQueue.Put(@Packet) + else + av_free_packet(@Packet); + + finally + UnlockParser(); + end; + end; +end; + + +(******************************************** + * Decoder section + ********************************************) + +procedure TFFmpegDecodeStream.PauseDecoder(); +begin + SDL_mutexP(StateLock); + Inc(DecoderPauseRequestCount); + while (DecoderLocked) do + SDL_CondWait(DecoderUnlockedCond, StateLock); + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.ResumeDecoder(); +begin + SDL_mutexP(StateLock); + Dec(DecoderPauseRequestCount); + SDL_CondSignal(DecoderResumeCond); + SDL_mutexV(StateLock); +end; + +procedure TFFmpegDecodeStream.FlushCodecBuffers(); +begin + // if no flush operation is specified, avcodec_flush_buffers will not do anything. + if (@CodecCtx.codec.flush <> nil) then + begin + // flush buffers used by avcodec_decode_audio, etc. + avcodec_flush_buffers(CodecCtx); + end + else + begin + // we need a Workaround to avoid plopping noise with ogg-vorbis and + // mp3 (in older versions of FFmpeg). + // We will just reopen the codec. + FFmpegCore.LockAVCodec(); + try + avcodec_close(CodecCtx); + avcodec_open(CodecCtx, Codec); + finally + FFmpegCore.UnlockAVCodec(); + end; + end; +end; + +function TFFmpegDecodeStream.DecodeFrame(Buffer: PChar; BufferSize: integer): integer; +var + PaketDecodedSize: integer; // size of packet data used for decoding + DataSize: integer; // size of output data decoded by FFmpeg + BlockQueue: boolean; + SilenceDuration: double; + {$IFDEF DebugFFmpegDecode} + TmpPos: double; + {$ENDIF} +begin + Result := -1; + + if (EOF) then + Exit; + + while(true) do + begin + // for titles with start_time > 0 we have to generate silence + // until we reach the pts of the first data packet. + if (AudioPaketSilence > 0) then + begin + DataSize := Min(AudioPaketSilence, BufferSize); + FillChar(Buffer[0], DataSize, 0); + Dec(AudioPaketSilence, DataSize); + AudioStreamPos := AudioStreamPos + DataSize / FormatInfo.BytesPerSec; + Result := DataSize; + Exit; + end; + + // read packet data + while (AudioPaketSize > 0) do + begin + DataSize := BufferSize; + + {$IF LIBAVCODEC_VERSION >= 51030000} // 51.30.0 + PaketDecodedSize := avcodec_decode_audio2(CodecCtx, PSmallint(Buffer), + DataSize, AudioPaketData, AudioPaketSize); + {$ELSE} + PaketDecodedSize := avcodec_decode_audio(CodecCtx, PSmallint(Buffer), + DataSize, AudioPaketData, AudioPaketSize); + {$IFEND} + + if(PaketDecodedSize < 0) then + begin + // if error, skip frame + {$IFDEF DebugFFmpegDecode} + DebugWriteln('Skip audio frame'); + {$ENDIF} + AudioPaketSize := 0; + Break; + end; + + Inc(AudioPaketData, PaketDecodedSize); + Dec(AudioPaketSize, PaketDecodedSize); + + // check if avcodec_decode_audio returned data, otherwise fetch more frames + if (DataSize <= 0) then + Continue; + + // update stream position by the amount of fetched data + AudioStreamPos := AudioStreamPos + DataSize / FormatInfo.BytesPerSec; + + // we have data, return it and come back for more later + Result := DataSize; + Exit; + end; + + // free old packet data + if (AudioPaket.data <> nil) then + av_free_packet(@AudioPaket); + + // do not block queue on seeking (to avoid deadlocks on the DecoderLock) + if (IsSeeking()) then + BlockQueue := false + else + BlockQueue := true; + + // request a new packet and block if none available. + // If this fails, the queue was aborted. + if (PacketQueue.Get(AudioPaket, BlockQueue) <= 0) then + Exit; + + // handle Status-packet + if (PChar(AudioPaket.data) = STATUS_PACKET) then + begin + AudioPaket.data := nil; + AudioPaketData := nil; + AudioPaketSize := 0; + + case (AudioPaket.flags) of + PKT_STATUS_FLAG_FLUSH: + begin + // just used if SetPositionIntern was called without the flush flag. + FlushCodecBuffers; + end; + PKT_STATUS_FLAG_EOF: // end-of-file + begin + // ignore EOF while seeking + if (not IsSeeking()) then + SetEOF(true); + // buffer contains no data -> result = -1 + Exit; + end; + PKT_STATUS_FLAG_ERROR: + begin + SetError(true); + Log.LogStatus('I/O Error', 'TFFmpegDecodeStream.DecodeFrame'); + Exit; + end; + PKT_STATUS_FLAG_EMPTY: + begin + SilenceDuration := PDouble(PacketQueue.GetStatusInfo(AudioPaket))^; + AudioPaketSilence := Round(SilenceDuration * FormatInfo.SampleRate) * FormatInfo.FrameSize; + PacketQueue.FreeStatusInfo(AudioPaket); + end + else + begin + Log.LogStatus('Unknown status', 'TFFmpegDecodeStream.DecodeFrame'); + end; + end; + + Continue; + end; + + AudioPaketData := PChar(AudioPaket.data); + AudioPaketSize := AudioPaket.size; + + // if available, update the stream position to the presentation time of this package + if(AudioPaket.pts <> AV_NOPTS_VALUE) then + begin + {$IFDEF DebugFFmpegDecode} + TmpPos := AudioStreamPos; + {$ENDIF} + AudioStreamPos := av_q2d(AudioStream^.time_base) * AudioPaket.pts; + {$IFDEF DebugFFmpegDecode} + DebugWriteln('Timestamp: ' + floattostrf(AudioStreamPos, ffFixed, 15, 3) + ' ' + + '(Calc: ' + floattostrf(TmpPos, ffFixed, 15, 3) + '), ' + + 'Diff: ' + floattostrf(AudioStreamPos-TmpPos, ffFixed, 15, 3)); + {$ENDIF} + end; + end; +end; + +function TFFmpegDecodeStream.ReadData(Buffer: PChar; BufferSize: integer): integer; +var + CopyByteCount: integer; // number of bytes to copy + RemainByteCount: integer; // number of bytes left (remain) to read + BufferPos: integer; + + // prioritize pause requests + procedure LockDecoder(); + begin + SDL_mutexP(StateLock); + while (DecoderPauseRequestCount > 0) do + SDL_CondWait(DecoderResumeCond, StateLock); + DecoderLocked := true; + SDL_mutexV(StateLock); + end; + + procedure UnlockDecoder(); + begin + SDL_mutexP(StateLock); + DecoderLocked := false; + SDL_CondBroadcast(DecoderUnlockedCond); + SDL_mutexV(StateLock); + end; + +begin + Result := -1; + + // set number of bytes to copy to the output buffer + BufferPos := 0; + + LockDecoder(); + try + // leave if end-of-file is reached + if (EOF) then + Exit; + + // copy data to output buffer + while (BufferPos < BufferSize) do + begin + // check if we need more data + if (AudioBufferPos >= AudioBufferSize) then + begin + AudioBufferPos := 0; + + // we have already sent all our data; get more + AudioBufferSize := DecodeFrame(AudioBuffer, AUDIO_BUFFER_SIZE); + + // check for errors or EOF + if(AudioBufferSize < 0) then + begin + Result := BufferPos; + Exit; + end; + end; + + // calc number of new bytes in the decode-buffer + CopyByteCount := AudioBufferSize - AudioBufferPos; + // resize copy-count if more bytes available than needed (remaining bytes are used the next time) + RemainByteCount := BufferSize - BufferPos; + if (CopyByteCount > RemainByteCount) then + CopyByteCount := RemainByteCount; + + Move(AudioBuffer[AudioBufferPos], Buffer[BufferPos], CopyByteCount); + + Inc(BufferPos, CopyByteCount); + Inc(AudioBufferPos, CopyByteCount); + end; + finally + UnlockDecoder(); + end; + + Result := BufferSize; +end; + + +{ TAudioDecoder_FFmpeg } + +function TAudioDecoder_FFmpeg.GetName: String; +begin + Result := 'FFmpeg_Decoder'; +end; + +function TAudioDecoder_FFmpeg.InitializeDecoder: boolean; +begin + //Log.LogStatus('InitializeDecoder', 'UAudioDecoder_FFmpeg'); + FFmpegCore := TMediaCore_FFmpeg.GetInstance(); + av_register_all(); + + // Do not show uninformative error messages by default. + // FFmpeg prints all error-infos on the console by default what + // is very confusing as the playback of the files is correct. + // We consider these errors to be internal to FFMpeg. They can be fixed + // by the FFmpeg guys only and do not provide any useful information in + // respect to USDX. + {$IFNDEF EnableFFmpegErrorOutput} + {$IF LIBAVUTIL_VERSION_MAJOR >= 50} + av_log_set_level(AV_LOG_FATAL); + {$ELSE} + // FATAL and ERROR share one log-level, so we have to use QUIET + av_log_set_level(AV_LOG_QUIET); + {$IFEND} + {$ENDIF} + + Result := true; +end; + +function TAudioDecoder_FFmpeg.FinalizeDecoder(): boolean; +begin + Result := true; +end; + +function TAudioDecoder_FFmpeg.Open(const Filename: string): TAudioDecodeStream; +var + Stream: TFFmpegDecodeStream; +begin + Result := nil; + + Stream := TFFmpegDecodeStream.Create(); + if (not Stream.Open(Filename)) then + begin + Stream.Free; + Exit; + end; + + Result := Stream; +end; + + +initialization + MediaManager.Add(TAudioDecoder_FFmpeg.Create); + +end. |