Motown: ffmpeg implementations of framework 'parts'

services/media/framework_ffmpeg/ffmpeg_video_decoder.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/logging.h"
+#include "services/media/framework_ffmpeg/ffmpeg_video_decoder.h"
+
+namespace mojo {
+namespace media {
+
+FfmpegVideoDecoder::FfmpegVideoDecoder(AVCodecContext *av_codec_context) :
+    FfmpegDecoderBase(av_codec_context) {
+  DCHECK(av_codec_context_);
+}
+
+FfmpegVideoDecoder::~FfmpegVideoDecoder() {}
+
+int FfmpegVideoDecoder::Decode(
+    PayloadAllocator* allocator,
+    bool* frame_decoded_out) {
+  DCHECK(allocator);
+  DCHECK(frame_decoded_out);
+  DCHECK(av_codec_context_);
+  DCHECK(av_frame_);
+
+  int frame_decoded = 0;
+  int input_bytes_used = avcodec_decode_video2(
+    av_codec_context_.get(),
+    av_frame_.get(),
+    &frame_decoded,
+    &av_packet_);
+  *frame_decoded_out = frame_decoded != 0;
+  return input_bytes_used;
+}
+
+PacketPtr FfmpegVideoDecoder::CreateOutputPacket(PayloadAllocator* allocator) {
+  DCHECK(allocator);
+  DCHECK(av_frame_);
+
+  // End of stream is indicated when we're draining and produce no packet.
+  // TODO(dalesat): This is just a copy of the audio version.
+  return Packet::Create(
+      av_frame_->pts,
+      av_frame_->pkt_duration,
+      false,
+      packet_size_,
+      av_frame_->data[0],
+      allocator);
+}
+
+int FfmpegVideoDecoder::AllocateBufferForAvFrame(
+    AVCodecContext* av_codec_context,
+    AVFrame* av_frame,
+    int flags) {
+  // It's important to use av_codec_context here rather than av_codec_context_,
+  // because av_codec_context is different for different threads when we're
+  // decoding on multiple threads. If this code is moved to an instance method,
+  // be sure to avoid using av_codec_context_.
+
+  // TODO(dalesat): Not sure why/if this is needed.
+  //int result = av_image_check_size(
+  //    av_codec_context->width,
+  //    av_codec_context->height,
+  //    0,
+  //    NULL);
+  //if (result < 0) {
+  //  DCHECK(false) << "av_image_check_size failed";
+  //  return result;
+  //}
+
+  // TODO(dalesat): Not sure why this is needed.
+  int coded_width =
+      std::max(av_codec_context->width, av_codec_context->coded_width);
+  int coded_height =
+      std::max(av_codec_context->height, av_codec_context->coded_height);
+  DCHECK_EQ(coded_width, av_codec_context->coded_width) <<
+      "coded width is less than width";
+  DCHECK_EQ(coded_height, av_codec_context->coded_height) <<
+      "coded height is less than height";
+
+  // TODO(dalesat): Fill in av_frame->data and av_frame->data for each plane.
+
+  av_frame->width = coded_width;
+  av_frame->height = coded_height;
+  av_frame->format = av_codec_context->pix_fmt;
+  av_frame->reordered_opaque = av_codec_context->reordered_opaque;
+
+  av_frame->buf[0] = av_buffer_create(
+      av_frame->data[0], // Because this is the first chunk in the buffer.
+      0, // TODO(dalesat): Provide this.
+      ReleaseBufferForAvFrame,
+      nullptr, // opaque
+      0); // flags
+
+  return 0;
+}
+
+void FfmpegVideoDecoder::ReleaseBufferForAvFrame(
+  void* opaque, uint8_t* buffer) {
+  // Nothing to do.
+  // TODO(dalesat): Can we get rid of this method altogether?
+}
+
+} // namespace media
+} // namespace mojo