Collapse FFmpegVideoDecodeEngine into FFmpegVideoDecoder and remove VideoDecodeEngine.

media/filters/ffmpeg_video_decoder.cc

Index: media/filters/ffmpeg_video_decoder.cc
diff --git a/media/filters/ffmpeg_video_decoder.cc b/media/filters/ffmpeg_video_decoder.cc
index 0254f6352149110c9c49ad388df92ce9587a69e4..39d9e3987841bf3f680915932d84c7d2bb014d44 100644
--- a/media/filters/ffmpeg_video_decoder.cc
+++ b/media/filters/ffmpeg_video_decoder.cc
@@ -5,24 +5,63 @@
 #include "media/filters/ffmpeg_video_decoder.h"
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/message_loop.h"
+#include "base/string_number_conversions.h"
 #include "media/base/demuxer_stream.h"
 #include "media/base/filter_host.h"
 #include "media/base/limits.h"
+#include "media/base/media_switches.h"
 #include "media/base/video_decoder_config.h"
 #include "media/base/video_frame.h"
+#include "media/base/video_util.h"
 #include "media/ffmpeg/ffmpeg_common.h"
-#include "media/video/ffmpeg_video_decode_engine.h"
 
 namespace media {
 
+// Always try to use three threads for video decoding.  There is little reason
+// not to since current day CPUs tend to be multi-core and we measured
+// performance benefits on older machines such as P4s with hyperthreading.
+//
+// Handling decoding on separate threads also frees up the pipeline thread to
+// continue processing. Although it'd be nice to have the option of a single
+// decoding thread, FFmpeg treats having one thread the same as having zero
+// threads (i.e., avcodec_decode_video() will execute on the calling thread).
+// Yet another reason for having two threads :)
+static const int kDecodeThreads = 2;
+static const int kMaxDecodeThreads = 16;
+
+// Returns the number of threads given the FFmpeg CodecID. Also inspects the
+// command line for a valid --video-threads flag.
+static int GetThreadCount(CodecID codec_id) {
+  // TODO(scherkus): As of 07/21/2011 we still can't enable Theora multithreaded
+  // decoding due to bugs in FFmpeg. Dig in and send fixes upstream!
+  //
+  // Refer to http://crbug.com/93932 for tsan suppressions on decoding.
+  int decode_threads = (codec_id == CODEC_ID_THEORA ? 1 : kDecodeThreads);
+
+  const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+  std::string threads(cmd_line->GetSwitchValueASCII(switches::kVideoThreads));
+  if (threads.empty() || !base::StringToInt(threads, &decode_threads))
+    return decode_threads;
+
+  decode_threads = std::max(decode_threads, 0);
+  decode_threads = std::min(decode_threads, kMaxDecodeThreads);
+  return decode_threads;
+}
+
 FFmpegVideoDecoder::FFmpegVideoDecoder(MessageLoop* message_loop)
     : message_loop_(message_loop),
       state_(kUninitialized),
-      decode_engine_(new FFmpegVideoDecodeEngine()) {
+      codec_context_(NULL),
+      av_frame_(NULL),
+      frame_rate_numerator_(0),
+      frame_rate_denominator_(0) {
 }
 
-FFmpegVideoDecoder::~FFmpegVideoDecoder() {}
+FFmpegVideoDecoder::~FFmpegVideoDecoder() {
+  ReleaseFFmpegResources();
+}
 
 void FFmpegVideoDecoder::Initialize(DemuxerStream* demuxer_stream,
                                     const base::Closure& callback,
@@ -71,16 +110,36 @@ void FFmpegVideoDecoder::Initialize(DemuxerStream* demuxer_stream,
     return;
   }
 
-  pts_stream_.Initialize(GetFrameDuration(config));
-  natural_size_ = config.natural_size();
+  // Initialize AVCodecContext structure.
+  codec_context_ = avcodec_alloc_context();
+  VideoDecoderConfigToAVCodecContext(config, codec_context_);
 
-  if (!decode_engine_->Initialize(config)) {
+  // Enable motion vector search (potentially slow), strong deblocking filter
+  // for damaged macroblocks, and set our error detection sensitivity.
+  codec_context_->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
+  codec_context_->error_recognition = FF_ER_CAREFUL;
+  codec_context_->thread_count = GetThreadCount(codec_context_->codec_id);
+
+  AVCodec* codec = avcodec_find_decoder(codec_context_->codec_id);
+  if (!codec) {
     host()->SetError(PIPELINE_ERROR_DECODE);
     callback.Run();
     return;
   }
 
+  if (avcodec_open(codec_context_, codec) < 0) {
+    host()->SetError(PIPELINE_ERROR_DECODE);
+    callback.Run();
+    return;
+  }
+
+  // Success!
   state_ = kNormal;
+  av_frame_ = avcodec_alloc_frame();
+  pts_stream_.Initialize(GetFrameDuration(config));
+  natural_size_ = config.natural_size();
+  frame_rate_numerator_ = config.frame_rate_numerator();
+  frame_rate_denominator_ = config.frame_rate_denominator();
   callback.Run();
 }
 
@@ -91,7 +150,7 @@ void FFmpegVideoDecoder::Stop(const base::Closure& callback) {
     return;
   }
 
-  decode_engine_->Uninitialize();
+  ReleaseFFmpegResources();
   state_ = kUninitialized;
   callback.Run();
 }
@@ -124,7 +183,7 @@ void FFmpegVideoDecoder::Flush(const base::Closure& callback) {
     return;
   }
 
-  decode_engine_->Flush();
+  avcodec_flush_buffers(codec_context_);
   pts_stream_.Flush();
   state_ = kNormal;
   callback.Run();
@@ -221,7 +280,7 @@ void FFmpegVideoDecoder::DoDecodeBuffer(const scoped_refptr<Buffer>& buffer) {
   }
 
   scoped_refptr<VideoFrame> video_frame;
-  if (!decode_engine_->Decode(buffer, &video_frame)) {
+  if (!Decode(buffer, &video_frame)) {
     state_ = kDecodeFinished;
     DeliverFrame(VideoFrame::CreateEmptyFrame());
     host()->SetError(PIPELINE_ERROR_DECODE);
@@ -256,6 +315,101 @@ void FFmpegVideoDecoder::DoDecodeBuffer(const scoped_refptr<Buffer>& buffer) {
   DeliverFrame(video_frame);
 }
 
+bool FFmpegVideoDecoder::Decode(
+    const scoped_refptr<Buffer>& buffer,
+    scoped_refptr<VideoFrame>* video_frame) {
+  DCHECK(video_frame);
+
+  // Create a packet for input data.
+  // Due to FFmpeg API changes we no longer have const read-only pointers.
+  AVPacket packet;
+  av_init_packet(&packet);
+  packet.data = const_cast<uint8*>(buffer->GetData());
+  packet.size = buffer->GetDataSize();
+
+  // Let FFmpeg handle presentation timestamp reordering.
+  codec_context_->reordered_opaque = buffer->GetTimestamp().InMicroseconds();
+
+  // This is for codecs not using get_buffer to initialize
+  // |av_frame_->reordered_opaque|
+  av_frame_->reordered_opaque = codec_context_->reordered_opaque;
+
+  int frame_decoded = 0;
+  int result = avcodec_decode_video2(codec_context_,
+                                     av_frame_,
+                                     &frame_decoded,
+                                     &packet);
+  // Log the problem if we can't decode a video frame and exit early.
+  if (result < 0) {
+    LOG(ERROR) << "Error decoding a video frame with timestamp: "
+               << buffer->GetTimestamp().InMicroseconds() << " us, duration: "
+               << buffer->GetDuration().InMicroseconds() << " us, packet size: "
+               << buffer->GetDataSize() << " bytes";
+    *video_frame = NULL;
+    return false;
+  }
+
+  // If no frame was produced then signal that more data is required to
+  // produce more frames. This can happen under two circumstances:
+  //   1) Decoder was recently initialized/flushed
+  //   2) End of stream was reached and all internal frames have been output
+  if (frame_decoded == 0) {
+    *video_frame = NULL;
+    return true;
+  }
+
+  // TODO(fbarchard): Work around for FFmpeg http://crbug.com/27675
+  // The decoder is in a bad state and not decoding correctly.
+  // Checking for NULL avoids a crash in CopyPlane().
+  if (!av_frame_->data[VideoFrame::kYPlane] ||
+      !av_frame_->data[VideoFrame::kUPlane] ||
+      !av_frame_->data[VideoFrame::kVPlane]) {
+    LOG(ERROR) << "Video frame was produced yet has invalid frame data.";
+    *video_frame = NULL;
+    return false;
+  }
+
+  // We've got a frame! Make sure we have a place to store it.
+  *video_frame = AllocateVideoFrame();
+  if (!(*video_frame)) {
+    LOG(ERROR) << "Failed to allocate video frame";
+    return false;
+  }
+
+  // Determine timestamp and calculate the duration based on the repeat picture
+  // count.  According to FFmpeg docs, the total duration can be calculated as
+  // follows:
+  //   fps = 1 / time_base
+  //
+  //   duration = (1 / fps) + (repeat_pict) / (2 * fps)
+  //            = (2 + repeat_pict) / (2 * fps)
+  //            = (2 + repeat_pict) / (2 * (1 / time_base))
+  DCHECK_LE(av_frame_->repeat_pict, 2);  // Sanity check.
+  AVRational doubled_time_base;
+  doubled_time_base.num = frame_rate_denominator_;
+  doubled_time_base.den = frame_rate_numerator_ * 2;
+
+  (*video_frame)->SetTimestamp(
+      base::TimeDelta::FromMicroseconds(av_frame_->reordered_opaque));
+  (*video_frame)->SetDuration(
+      ConvertFromTimeBase(doubled_time_base, 2 + av_frame_->repeat_pict));
+
+  // Copy the frame data since FFmpeg reuses internal buffers for AVFrame
+  // output, meaning the data is only valid until the next
+  // avcodec_decode_video() call.
+  int y_rows = codec_context_->height;
+  int uv_rows = codec_context_->height;
+  if (codec_context_->pix_fmt == PIX_FMT_YUV420P) {
+    uv_rows /= 2;
+  }
+
+  CopyYPlane(av_frame_->data[0], av_frame_->linesize[0], y_rows, *video_frame);
+  CopyUPlane(av_frame_->data[1], av_frame_->linesize[1], uv_rows, *video_frame);
+  CopyVPlane(av_frame_->data[2], av_frame_->linesize[2], uv_rows, *video_frame);
+
+  return true;
+}
+
 void FFmpegVideoDecoder::DeliverFrame(
     const scoped_refptr<VideoFrame>& video_frame) {
   // Reset the callback before running to protect against reentrancy.
@@ -264,4 +418,26 @@ void FFmpegVideoDecoder::DeliverFrame(
   read_cb.Run(video_frame);
 }
 
+void FFmpegVideoDecoder::ReleaseFFmpegResources() {
+  if (codec_context_) {
+    av_free(codec_context_->extradata);
+    avcodec_close(codec_context_);
+    av_free(codec_context_);
+    codec_context_ = NULL;
+  }
+  if (av_frame_) {
+    av_free(av_frame_);
+    av_frame_ = NULL;
+  }
+}
+
+scoped_refptr<VideoFrame> FFmpegVideoDecoder::AllocateVideoFrame() {
+  VideoFrame::Format format = PixelFormatToVideoFormat(codec_context_->pix_fmt);
+  size_t width = codec_context_->width;
+  size_t height = codec_context_->height;
+
+  return VideoFrame::CreateFrame(format, width, height,
+                                 kNoTimestamp, kNoTimestamp);
+}
+
 }  // namespace media