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// Copyright (c) 2010 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.
//
// Borrowed from media/tools/omx_test/file_reader_util.cc.
// Added some functionalities related to timestamps on packets.
#include "media/mf/file_reader_util.h"
#include <cstring>
#include <algorithm>
#include "base/scoped_comptr_win.h"
#include "base/logging.h"
#include "media/ffmpeg/ffmpeg_common.h"
#include "media/filters/bitstream_converter.h"
namespace media {
//////////////////////////////////////////////////////////////////////////////
// FFmpegFileReader
FFmpegFileReader::FFmpegFileReader(const std::string& filename)
: filename_(filename),
format_context_(NULL),
codec_context_(NULL),
target_stream_(-1),
converter_(NULL),
end_of_stream_(false) {
}
FFmpegFileReader::~FFmpegFileReader() {
if (format_context_)
av_close_input_file(format_context_);
}
bool FFmpegFileReader::Initialize() {
int result = av_open_input_file(&format_context_, filename_.c_str(),
NULL, 0, NULL);
if (result < 0) {
switch (result) {
case AVERROR_NOFMT:
LOG(ERROR) << "Error: File format not supported "
<< filename_;
break;
default:
LOG(ERROR) << "Error: Could not open input for "
<< filename_ << ": " << result;
break;
}
return false;
}
if (av_find_stream_info(format_context_) < 0) {
LOG(ERROR) << "can't use FFmpeg to parse stream info";
return false;
}
for (size_t i = 0; i < format_context_->nb_streams; ++i) {
codec_context_ = format_context_->streams[i]->codec;
// Find the video stream.
if (codec_context_->codec_type == CODEC_TYPE_VIDEO) {
target_stream_ = i;
break;
}
}
if (target_stream_ == -1) {
LOG(ERROR) << "no video in the stream";
return false;
}
// Initialize the bitstream filter if needed.
// TODO(hclam): find a better way to identify mp4 container.
if (codec_context_->codec_id == CODEC_ID_H264) {
converter_.reset(new media::FFmpegBitstreamConverter(
"h264_mp4toannexb", codec_context_));
} else if (codec_context_->codec_id == CODEC_ID_MPEG4) {
converter_.reset(new media::FFmpegBitstreamConverter(
"mpeg4video_es", codec_context_));
} else if (codec_context_->codec_id == CODEC_ID_WMV3) {
converter_.reset(new media::FFmpegBitstreamConverter(
"vc1_asftorcv", codec_context_));
} else if (codec_context_->codec_id == CODEC_ID_VC1) {
converter_.reset(new media::FFmpegBitstreamConverter(
"vc1_asftoannexg", codec_context_));
}
if (converter_.get() && !converter_->Initialize()) {
converter_.reset();
LOG(ERROR) << "failed to initialize h264_mp4toannexb filter";
return false;
}
return true;
}
void FFmpegFileReader::Read(uint8** output, int* size) {
Read2(output, size, NULL, NULL);
}
void FFmpegFileReader::Read2(uint8** output, int* size, int64* timestamp,
int64* duration) {
if (!format_context_ || !codec_context_ || target_stream_ == -1) {
*size = 0;
*output = NULL;
return;
}
AVPacket packet;
bool found = false;
while (!found) {
int result = av_read_frame(format_context_, &packet);
if (result < 0) {
*output = NULL;
*size = 0;
end_of_stream_ = true;
return;
}
if (packet.stream_index == target_stream_) {
if (converter_.get() && !converter_->ConvertPacket(&packet)) {
LOG(ERROR) << "failed to convert AVPacket";
}
*output = new uint8[packet.size];
if (*output == NULL) {
LOG(ERROR) << "Failed to allocate buffer for annex b stream";
*size = 0;
return;
}
*size = packet.size;
memcpy(*output, packet.data, packet.size);
if (duration) {
if (packet.duration == 0) {
LOG(WARNING) << "Packet duration not known";
}
// This is in AVCodecContext::time_base units
*duration = ConvertFFmpegTimeBaseTo100Ns(packet.duration);
}
if (timestamp) {
if (packet.pts == AV_NOPTS_VALUE) {
LOG(ERROR) << "Packet presentation time not known";
*timestamp = 0L;
} else {
// This is in AVCodecContext::time_base units
*timestamp = ConvertFFmpegTimeBaseTo100Ns(packet.pts);
}
}
found = true;
}
av_free_packet(&packet);
}
}
bool FFmpegFileReader::GetFrameRate(int* num, int* denom) const {
if (!codec_context_)
return false;
*denom = codec_context_->time_base.num;
*num = codec_context_->time_base.den;
if (*denom == 0) {
*num = 0;
return false;
}
return true;
}
bool FFmpegFileReader::GetWidth(int* width) const {
if (!codec_context_)
return false;
*width = codec_context_->width;
return true;
}
bool FFmpegFileReader::GetHeight(int* height) const {
if (!codec_context_)
return false;
*height = codec_context_->height;
return true;
}
bool FFmpegFileReader::GetAspectRatio(int* num, int* denom) const {
if (!codec_context_)
return false;
AVRational aspect_ratio = codec_context_->sample_aspect_ratio;
if (aspect_ratio.num == 0 || aspect_ratio.den == 0)
return false;
*num = aspect_ratio.num;
*denom = aspect_ratio.den;
return true;
}
int64 FFmpegFileReader::ConvertFFmpegTimeBaseTo100Ns(
int64 time_base_unit) const {
// FFmpeg units after time base conversion seems to be actually given in
// milliseconds (instead of seconds...) so we need to multiply it by a factor
// of 10,000 to convert it into units compatible with MF.
// Note we need to double this because the frame rate is doubled in
// ffmpeg.
CHECK(codec_context_) << "Codec context needs to be initialized";
return time_base_unit * 20000 * codec_context_->time_base.num /
codec_context_->time_base.den;
}
} // namespace media
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