Implemented HEVC video demuxing and parsing

media/filters/ffmpeg_h265_to_annex_b_bitstream_converter.cc

+// Copyright 2015 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_h265_to_annex_b_bitstream_converter.h"
+
+#include "base/logging.h"
+#include "media/base/decrypt_config.h"
+#include "media/ffmpeg/ffmpeg_common.h"
+#include "media/formats/mp4/avc.h"
+#include "media/formats/mp4/box_definitions.h"
+#include "media/formats/mp4/hevc.h"
+
+namespace media {
+
+FFmpegH265ToAnnexBBitstreamConverter::FFmpegH265ToAnnexBBitstreamConverter(
+    AVCodecContext* stream_codec_context)
+    : stream_codec_context_(stream_codec_context) {
+  CHECK(stream_codec_context_);
+}
+
+FFmpegH265ToAnnexBBitstreamConverter::~FFmpegH265ToAnnexBBitstreamConverter() {}
+
+bool FFmpegH265ToAnnexBBitstreamConverter::ConvertPacket(AVPacket* packet) {
+  DVLOG(3) << __FUNCTION__;
+  if (packet == NULL || !packet->data)
+    return false;
+
+  // Calculate the needed output buffer size.
+  if (!hevc_config_) {
+    if (!stream_codec_context_->extradata ||
+        stream_codec_context_->extradata_size <= 0) {
+      DVLOG(1) << "HEVCDecoderConfiguration not found, no extra codec data";
+      return false;
+    }
+
+    hevc_config_.reset(new mp4::HEVCDecoderConfigurationRecord());
+
+    if (!hevc_config_->Parse(
+            stream_codec_context_->extradata,
+            stream_codec_context_->extradata_size)) {
+      DVLOG(1) << "Parsing HEVCDecoderConfiguration failed";
+      return false;
+    }
+  }
+
+  std::vector<uint8> input_frame;
+  std::vector<SubsampleEntry> subsamples;
+  // TODO(servolk): Performance could be improved here, by reducing unnecessary
+  // data copying, but first annex b conversion code needs to be refactored to
+  // allow that (see crbug.com/455379).
+  input_frame.insert(input_frame.end(),
+                     packet->data, packet->data + packet->size);
+  int nalu_size_len = hevc_config_->lengthSizeMinusOne + 1;
+  if (!mp4::AVC::ConvertFrameToAnnexB(nalu_size_len, &input_frame,
+                                      &subsamples)) {
+    DVLOG(1) << "AnnexB conversion failed";
+    return false;
+  }
+
+  if (packet->flags & AV_PKT_FLAG_KEY) {
+    RCHECK(mp4::HEVC::InsertParamSetsAnnexB(*hevc_config_.get(),
+                                            &input_frame, &subsamples));
+    DVLOG(4) << "Inserted HEVC decoder params";
+  }
+
+  uint32 output_packet_size = input_frame.size();
+
+  if (output_packet_size == 0)
+    return false;  // Invalid input packet.
+
+  // Allocate new packet for the output.
+  AVPacket dest_packet;
+  if (av_new_packet(&dest_packet, output_packet_size) != 0)
+    return false;  // Memory allocation failure.
+
+  // This is a bit tricky: since the interface does not allow us to replace
+  // the pointer of the old packet with a new one, we will initially copy the
+  // metadata from old packet to new bigger packet.
+  av_packet_copy_props(&dest_packet, packet);
+
+  // Proceed with the conversion of the actual in-band NAL units, leave room
+  // for configuration in the beginning.
+  memcpy(dest_packet.data, &input_frame[0], input_frame.size());
+
+  // At the end we must destroy the old packet.
+  av_free_packet(packet);
+  *packet = dest_packet;  // Finally, replace the values in the input packet.
+
+  return true;
+}
+
+}  // namespace media