Allow to use {FFmpeg/Vpx}VideoDecoder from a UtilityProcess

media/filters/ffmpeg_video_decoder.cc

 // Copyright (c) 2012 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 "media/filters/ffmpeg_video_decoder.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "media/base/bind_to_current_loop.h"
 #include "media/base/decoder_buffer.h"
 #include "media/base/limits.h"
 #include "media/base/media_switches.h"
 #include "media/base/timestamp_constants.h"
 #include "media/base/video_frame.h"
+#include "media/base/video_frame_provider.h"
 #include "media/base/video_util.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 #include "media/filters/ffmpeg_glue.h"
 
 namespace media {
 
 // Always use 2 or more threads for video decoding. Most machines today will
 // have 2-8 execution contexts. Using more cores generally doesn't seem to
 // increase power usage and allows us to decode video faster.
 //
@@ skipping 72 matching lines @@
 bool FFmpegVideoDecoder::IsCodecSupported(VideoCodec codec) {
   FFmpegGlue::InitializeFFmpeg();
   return avcodec_find_decoder(VideoCodecToCodecID(codec)) != nullptr;
 }
 
 FFmpegVideoDecoder::FFmpegVideoDecoder()
     : state_(kUninitialized), decode_nalus_(false) {
   thread_checker_.DetachFromThread();
 }
 
+FFmpegVideoDecoder::FFmpegVideoDecoder(
+    std::unique_ptr<VideoFrameProvider> video_frame_provider)
+    : state_(kUninitialized),
+      frame_pool_(std::move(video_frame_provider)),
+      decode_nalus_(false) {
+  thread_checker_.DetachFromThread();
+}
+
 int FFmpegVideoDecoder::GetVideoBuffer(struct AVCodecContext* codec_context,
                                        AVFrame* frame,
                                        int flags) {
   // Don't use |codec_context_| here! With threaded decoding,
   // it will contain unsynchronized width/height/pix_fmt values,
   // whereas |codec_context| contains the current threads's
   // updated width/height/pix_fmt, which can change for adaptive
   // content.
   const VideoPixelFormat format =
       AVPixelFormatToVideoPixelFormat(codec_context->pix_fmt);
@@ skipping 298 matching lines @@
   if (!codec || avcodec_open2(codec_context_.get(), codec, NULL) < 0) {
     ReleaseFFmpegResources();
     return false;
   }
 
   av_frame_.reset(av_frame_alloc());
   return true;
 }
 
 }  // namespace media