Reorganize bitstream converter classes.

media/filters/bitstream_converter.cc

-// Copyright (c) 2011 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/bitstream_converter.h"
-
-#include "base/logging.h"
-#include "media/ffmpeg/ffmpeg_common.h"
-
-namespace media {
-
-bool IdentityBitstreamConverter::Initialize() {
-  return true;
-}
-
-bool IdentityBitstreamConverter::ConvertPacket(AVPacket* packet) {
-  return true;
-}
-
-FFmpegBitstreamConverter::FFmpegBitstreamConverter(
-    const std::string& filter_name,
-    AVCodecContext* stream_context)
-    : filter_name_(filter_name),
-      stream_filter_(NULL),
-      stream_context_(stream_context) {
-  CHECK(stream_context_);
-}
-
-FFmpegBitstreamConverter::~FFmpegBitstreamConverter() {
-  if (stream_filter_) {
-    av_bitstream_filter_close(stream_filter_);
-    stream_filter_ = NULL;
-  }
-}
-
-bool FFmpegBitstreamConverter::Initialize() {
-  stream_filter_ = av_bitstream_filter_init(filter_name_.c_str());
-  return stream_filter_ != NULL;
-}
-
-bool FFmpegBitstreamConverter::ConvertPacket(AVPacket* packet) {
-  CHECK(packet);
-
-  if (!stream_filter_) {
-    LOG(ERROR) << "Converter improperly initialized.";
-    return false;
-  }
-
-  uint8_t* converted_data = NULL;
-  int converted_size = 0;
-
-  if (av_bitstream_filter_filter(stream_filter_, stream_context_, NULL,
-                                 &converted_data, &converted_size,
-                                 packet->data, packet->size,
-                                 packet->flags & AV_PKT_FLAG_KEY) < 0) {
-    return false;
-  }
-
-  // av_bitstream_filter_filter() does not always allocate a new packet.
-  // If a new packet was allocated, then we need to modify the
-  // |packet| to point to the new data, releasing its current payload
-  // if it has the authoritative reference.
-  //
-  // TODO(ajwong): We're relying on the implementation behavior of
-  // av_free_packet() and the meaning of the |destruct| field in
-  // AVPacket. Try to find a cleaner way to do this.
-  if (converted_data != packet->data) {
-    av_free_packet(packet);
-    packet->data = converted_data;
-    packet->size = converted_size;
-    packet->destruct = av_destruct_packet;
-  }
-
-  return true;
-}
-
-}  // namespace media