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matroskavideo.cpp

//  Copyright (c) 2007-2009 Fredrik Mellbin
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.

#include "videosource.h"



void FFMatroskaVideo::Free(bool CloseCodec) {
      if (CS)
            cs_Destroy(CS);
      if (MC.ST.fp) {
            mkv_Close(MF);
            fclose(MC.ST.fp);
      }
      if (CloseCodec)
            avcodec_close(CodecContext);
      av_freep(&CodecContext);
}

FFMatroskaVideo::FFMatroskaVideo(const char *SourceFile, int Track,
      FFMS_Index *Index, int Threads)
      : Res(FFSourceResources<FFMS_VideoSource>(this)), FFMS_VideoSource(SourceFile, Index, Track) {

      AVCodec *Codec = NULL;
      CodecContext = NULL;
      TrackInfo *TI = NULL;
      CS = NULL;
      PacketNumber = 0;
      VideoTrack = Track;
      Frames = (*Index)[VideoTrack];

      MC.ST.fp = ffms_fopen(SourceFile, "rb");
      if (MC.ST.fp == NULL) {
            std::ostringstream buf;
            buf << "Can't open '" << SourceFile << "': " << strerror(errno);
            throw FFMS_Exception(FFMS_ERROR_PARSER, FFMS_ERROR_FILE_READ, buf.str());
      }

      setvbuf(MC.ST.fp, NULL, _IOFBF, CACHESIZE);

      MF = mkv_OpenEx(&MC.ST.base, 0, 0, ErrorMessage, sizeof(ErrorMessage));
      if (MF == NULL) {
            fclose(MC.ST.fp);
            std::ostringstream buf;
            buf << "Can't parse Matroska file: " << ErrorMessage;
            throw FFMS_Exception(FFMS_ERROR_PARSER, FFMS_ERROR_FILE_READ, buf.str());
      }

      TI = mkv_GetTrackInfo(MF, VideoTrack);

      if (TI->CompEnabled) {
            CS = cs_Create(MF, VideoTrack, ErrorMessage, sizeof(ErrorMessage));
            if (CS == NULL) {
                  Free(false);
                  std::ostringstream buf;
                  buf << "Can't create decompressor: " << ErrorMessage;
                  throw FFMS_Exception(FFMS_ERROR_PARSER, FFMS_ERROR_FILE_READ, buf.str());
            }
      }

      CodecContext = avcodec_alloc_context();
      CodecContext->thread_count = Threads;

      Codec = avcodec_find_decoder(MatroskaToFFCodecID(TI->CodecID, TI->CodecPrivate));
      if (Codec == NULL)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_CODEC,
                  "Video codec not found");

      InitializeCodecContextFromMatroskaTrackInfo(TI, CodecContext);

      if (avcodec_open(CodecContext, Codec) < 0)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_CODEC,
                  "Could not open video codec");

      Res.CloseCodec(true);

      // Always try to decode a frame to make sure all required parameters are known
      DecodeNextFrame();

      VP.FPSDenominator = 1;
      VP.FPSNumerator = 30;
      VP.RFFDenominator = CodecContext->time_base.num;
      VP.RFFNumerator = CodecContext->time_base.den;
      if (CodecContext->codec_id == CODEC_ID_H264) {
            if (VP.RFFNumerator & 1)
                  VP.RFFDenominator *= 2;
            else
                  VP.RFFNumerator /= 2;
      }
      VP.NumFrames = Frames.size();
      VP.TopFieldFirst = DecodeFrame->top_field_first;
#ifdef FFMS_HAVE_FFMPEG_COLORSPACE_INFO
      VP.ColorSpace = CodecContext->colorspace;
      VP.ColorRange = CodecContext->color_range;
#else
      VP.ColorSpace = 0;
      VP.ColorRange = 0;
#endif
      VP.FirstTime = ((Frames.front().PTS * Frames.TB.Num) / (double)Frames.TB.Den) / 1000;
      VP.LastTime = ((Frames.back().PTS * Frames.TB.Num) / (double)Frames.TB.Den) / 1000;

      if (CodecContext->width <= 0 || CodecContext->height <= 0)
            throw FFMS_Exception(FFMS_ERROR_DECODING, FFMS_ERROR_CODEC,
                  "Codec returned zero size video");

      // Calculate the average framerate
      if (Frames.size() >= 2) {
            double PTSDiff = (double)(Frames.back().PTS - Frames.front().PTS);
            VP.FPSDenominator = (unsigned int)(PTSDiff * mkv_TruncFloat(TI->TimecodeScale) / (double)1000 / (double)(VP.NumFrames - 1) + 0.5);
            VP.FPSNumerator = 1000000; 
      }

      // attempt to correct framerate to the proper NTSC fraction, if applicable
      CorrectNTSCRationalFramerate(&VP.FPSNumerator, &VP.FPSDenominator);

      // Output the already decoded frame so it isn't wasted
      OutputFrame(DecodeFrame);

      // Set AR variables
      VP.SARNum = TI->AV.Video.DisplayWidth * TI->AV.Video.PixelHeight;
      VP.SARDen = TI->AV.Video.DisplayHeight * TI->AV.Video.PixelWidth;

      // Set crop variables
      VP.CropLeft = TI->AV.Video.CropL;
      VP.CropRight = TI->AV.Video.CropR;
      VP.CropTop = TI->AV.Video.CropT;
      VP.CropBottom = TI->AV.Video.CropB;
}

void FFMatroskaVideo::DecodeNextFrame() {
      int FrameFinished = 0;
      AVPacket Packet;
      InitNullPacket(Packet);

      unsigned int FrameSize;

      if (InitialDecode == -1) {
            if (DelayCounter > CodecContext->has_b_frames) {
                  DelayCounter--;
                  goto Done;
            } else {
                  InitialDecode = 0;
            }
      }
      
      while (PacketNumber < Frames.size()) {
            // The additional indirection is because the packets are stored in
            // presentation order and not decoding order, this is unnoticable
            // in the other sources where less is done manually
            const TFrameInfo &FI = Frames[Frames[PacketNumber].OriginalPos];
            FrameSize = FI.FrameSize;
            ReadFrame(FI.FilePos, FrameSize, CS, MC);

            Packet.data = MC.Buffer;
            Packet.size = FrameSize;
            if (FI.KeyFrame)
                  Packet.flags = AV_PKT_FLAG_KEY;
            else
                  Packet.flags = 0;

            PacketNumber++;

            avcodec_decode_video2(CodecContext, DecodeFrame, &FrameFinished, &Packet);

            if (!FrameFinished)
                  DelayCounter++;
            if (DelayCounter > CodecContext->has_b_frames && !InitialDecode)
                  goto Done;

            if (FrameFinished)
                  goto Done;
      }

      // Flush the last frames
      if (CodecContext->has_b_frames) {
            AVPacket NullPacket;
            InitNullPacket(NullPacket);
            avcodec_decode_video2(CodecContext, DecodeFrame, &FrameFinished, &NullPacket);
      }

      if (!FrameFinished)
            goto Error;

Error:
Done:
      if (InitialDecode == 1) InitialDecode = -1;
}

FFMS_Frame *FFMatroskaVideo::GetFrame(int n) {
      GetFrameCheck(n);

      if (LastFrameNum == n)
            return &LocalFrame;

      int ClosestKF = Frames.FindClosestVideoKeyFrame(n);
      if (CurrentFrame > n || ClosestKF > CurrentFrame + 10) {
            DelayCounter = 0;
            InitialDecode = 1;
            PacketNumber = ClosestKF;
            CurrentFrame = ClosestKF;
            avcodec_flush_buffers(CodecContext);
      }

      do {
            if (CurrentFrame+CodecContext->has_b_frames >= n)
                  CodecContext->skip_frame = AVDISCARD_DEFAULT;
            else
                  CodecContext->skip_frame = AVDISCARD_NONREF;
            DecodeNextFrame();
            CurrentFrame++;
      } while (CurrentFrame <= n);

      LastFrameNum = n;
      return OutputFrame(DecodeFrame);
}

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