#include "util.h"
#include "log.h"
#include "ffmpeg_decoder.h"
+#include "filter_graph.h"
#include "subtitle.h"
+#include "i18n.h"
+
using std::cout;
using std::string;
using std::vector;
using std::stringstream;
+using std::list;
using boost::shared_ptr;
-
-FFmpegDecoder::FFmpegDecoder (shared_ptr<Film> f, shared_ptr<const Options> o, Job* j, bool minimal, bool ignore_length)
- : Decoder (f, o, j, minimal, ignore_length)
+using boost::optional;
+using boost::dynamic_pointer_cast;
+using libdcp::Size;
+
+FFmpegDecoder::FFmpegDecoder (shared_ptr<Film> f, DecodeOptions o)
+ : Decoder (f, o)
+ , VideoDecoder (f, o)
+ , AudioDecoder (f, o)
, _format_context (0)
, _video_stream (-1)
- , _audio_stream (-1)
- , _subtitle_stream (-1)
, _frame (0)
, _video_codec_context (0)
, _video_codec (0)
setup_video ();
setup_audio ();
setup_subtitle ();
+
+ if (!o.video_sync) {
+ _first_video = 0;
+ }
}
FFmpegDecoder::~FFmpegDecoder ()
void
FFmpegDecoder::setup_general ()
{
- int r;
-
av_register_all ();
- if ((r = avformat_open_input (&_format_context, _film->content_path().c_str(), 0, 0)) != 0) {
+ if (avformat_open_input (&_format_context, _film->content_path().c_str(), 0, 0) < 0) {
throw OpenFileError (_film->content_path ());
}
if (avformat_find_stream_info (_format_context, 0) < 0) {
- throw DecodeError ("could not find stream information");
+ throw DecodeError (_("could not find stream information"));
}
/* Find video, audio and subtitle streams and choose the first of each */
if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
_video_stream = i;
} else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
- if (_audio_stream == -1) {
- _audio_stream = i;
+
+ /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
+ so bodge it here. No idea why we should have to do this.
+ */
+
+ if (s->codec->channel_layout == 0) {
+ s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels);
}
- _audio_streams.push_back (AudioStream (stream_name (s), i, s->codec->channels));
+
+ _audio_streams.push_back (
+ shared_ptr<AudioStream> (
+ new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channel_layout)
+ )
+ );
+
} else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
- if (_subtitle_stream == -1) {
- _subtitle_stream = i;
- }
- _subtitle_streams.push_back (SubtitleStream (stream_name (s), i));
+ _subtitle_streams.push_back (
+ shared_ptr<SubtitleStream> (
+ new SubtitleStream (stream_name (s), i)
+ )
+ );
}
}
- /* Now override audio and subtitle streams with those from the Film, if it has any */
-
- if (_film->audio_stream_index() != -1) {
- _audio_stream = _film->audio_stream().id();
- }
-
- if (_film->subtitle_stream_index() != -1) {
- _subtitle_stream = _film->subtitle_stream().id ();
- }
-
if (_video_stream < 0) {
- throw DecodeError ("could not find video stream");
+ throw DecodeError (N_("could not find video stream"));
}
_frame = avcodec_alloc_frame ();
if (_frame == 0) {
- throw DecodeError ("could not allocate frame");
+ throw DecodeError (N_("could not allocate frame"));
}
}
_video_codec = avcodec_find_decoder (_video_codec_context->codec_id);
if (_video_codec == 0) {
- throw DecodeError ("could not find video decoder");
+ throw DecodeError (_("could not find video decoder"));
}
- /* I think this prevents problems with green hash on decodes and
- "changing frame properties on the fly is not supported by all filters"
- messages with some content. Although I'm not sure; needs checking.
- */
- AVDictionary* opts = 0;
- av_dict_set (&opts, "threads", "1", 0);
-
- if (avcodec_open2 (_video_codec_context, _video_codec, &opts) < 0) {
- throw DecodeError ("could not open video decoder");
+ if (avcodec_open2 (_video_codec_context, _video_codec, 0) < 0) {
+ throw DecodeError (N_("could not open video decoder"));
}
}
void
FFmpegDecoder::setup_audio ()
{
- if (_audio_stream < 0) {
+ if (!_audio_stream) {
return;
}
+
+ shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
+ assert (ffa);
- _audio_codec_context = _format_context->streams[_audio_stream]->codec;
+ _audio_codec_context = _format_context->streams[ffa->id()]->codec;
_audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id);
if (_audio_codec == 0) {
- throw DecodeError ("could not find audio decoder");
+ throw DecodeError (_("could not find audio decoder"));
}
if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) {
- throw DecodeError ("could not open audio decoder");
- }
-
- /* This is a hack; sometimes it seems that _audio_codec_context->channel_layout isn't set up,
- so bodge it here. No idea why we should have to do this.
- */
-
- if (_audio_codec_context->channel_layout == 0) {
- _audio_codec_context->channel_layout = av_get_default_channel_layout (audio_channels ());
+ throw DecodeError (N_("could not open audio decoder"));
}
}
void
FFmpegDecoder::setup_subtitle ()
{
- if (_subtitle_stream < 0) {
+ if (!_subtitle_stream) {
return;
}
- _subtitle_codec_context = _format_context->streams[_subtitle_stream]->codec;
+ _subtitle_codec_context = _format_context->streams[_subtitle_stream->id()]->codec;
_subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id);
if (_subtitle_codec == 0) {
- throw DecodeError ("could not find subtitle decoder");
+ throw DecodeError (_("could not find subtitle decoder"));
}
if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
- throw DecodeError ("could not open subtitle decoder");
+ throw DecodeError (N_("could not open subtitle decoder"));
}
}
bool
-FFmpegDecoder::do_pass ()
+FFmpegDecoder::pass ()
{
int r = av_read_frame (_format_context, &_packet);
/* Maybe we should fail here, but for now we'll just finish off instead */
char buf[256];
av_strerror (r, buf, sizeof(buf));
- _film->log()->log (String::compose ("error on av_read_frame (%1) (%2)", buf, r));
+ _film->log()->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r));
}
/* Get any remaining frames */
int frame_finished;
while (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
- process_video (_frame);
+ filter_and_emit_video (_frame);
}
- if (_audio_stream >= 0 && _opt->decode_audio) {
+ if (_audio_stream && _opt.decode_audio) {
while (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
int const data_size = av_samples_get_buffer_size (
0, _audio_codec_context->channels, _frame->nb_samples, audio_sample_format (), 1
);
assert (_audio_codec_context->channels == _film->audio_channels());
- process_audio (_frame->data[0], data_size);
+ Audio (deinterleave_audio (_frame->data, data_size));
}
}
}
avcodec_get_frame_defaults (_frame);
-
+
+ shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
+
if (_packet.stream_index == _video_stream) {
int frame_finished;
if (r >= 0 && frame_finished) {
if (r != _packet.size) {
- _film->log()->log (String::compose ("Used only %1 bytes of %2 in packet", r, _packet.size));
- }
-
- /* Where we are in the output, in seconds */
- double const out_pts_seconds = video_frame_index() / frames_per_second();
-
- /* Where we are in the source, in seconds */
- double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
- * av_frame_get_best_effort_timestamp(_frame);
-
- if (!_first_video) {
- _first_video = source_pts_seconds;
+ _film->log()->log (String::compose (N_("Used only %1 bytes of %2 in packet"), r, _packet.size));
}
- /* Difference between where we are and where we should be */
- double const delta = source_pts_seconds - _first_video.get() - out_pts_seconds;
- double const one_frame = 1 / frames_per_second();
-
- /* Insert frames if required to get out_pts_seconds up to pts_seconds */
- if (delta > one_frame) {
- int const extra = rint (delta / one_frame);
- for (int i = 0; i < extra; ++i) {
- repeat_last_video ();
- _film->log()->log (
- String::compose (
- "Extra frame inserted at %1s; DCP frame %2, source PTS %3",
- out_pts_seconds, video_frame_index(), source_pts_seconds
- )
- );
- }
- }
-
- if (delta > -one_frame) {
- /* Process this frame */
- process_video (_frame);
+ if (_opt.video_sync) {
+ out_with_sync ();
} else {
- /* Otherwise we are omitting a frame to keep things right */
- _film->log()->log (String::compose ("Frame removed at %1s", out_pts_seconds));
+ filter_and_emit_video (_frame);
}
}
- } else if (_audio_stream >= 0 && _packet.stream_index == _audio_stream && _opt->decode_audio) {
+ } else if (ffa && _packet.stream_index == ffa->id() && _opt.decode_audio) {
int frame_finished;
if (avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
*/
/* frames of silence that we must push */
- int const s = rint ((_first_audio.get() - _first_video.get()) * audio_sample_rate ());
+ int const s = rint ((_first_audio.get() - _first_video.get()) * ffa->sample_rate ());
_film->log()->log (
String::compose (
- "First video at %1, first audio at %2, pushing %3 frames of silence for %4 channels (%5 bytes per sample)",
- _first_video.get(), _first_audio.get(), s, audio_channels(), bytes_per_audio_sample()
+ N_("First video at %1, first audio at %2, pushing %3 audio frames of silence for %4 channels (%5 bytes per sample)"),
+ _first_video.get(), _first_audio.get(), s, ffa->channels(), bytes_per_audio_sample()
)
);
if (s) {
- /* hence bytes */
- int const b = s * audio_channels() * bytes_per_audio_sample();
-
- /* XXX: this assumes that it won't be too much, and there are shaky assumptions
- that all sound representations are silent with memset()ed zero data.
- */
- uint8_t silence[b];
- memset (silence, 0, b);
- process_audio (silence, b);
+ shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), s));
+ audio->make_silent ();
+ Audio (audio);
}
}
);
assert (_audio_codec_context->channels == _film->audio_channels());
- process_audio (_frame->data[0], data_size);
+ Audio (deinterleave_audio (_frame->data, data_size));
}
}
- } else if (_subtitle_stream >= 0 && _packet.stream_index == _subtitle_stream && _opt->decode_subtitles && _first_video) {
+ } else if (_subtitle_stream && _packet.stream_index == _subtitle_stream->id() && _opt.decode_subtitles && _first_video) {
int got_subtitle;
AVSubtitle sub;
indicate that the previous subtitle should stop.
*/
if (sub.num_rects > 0) {
- process_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub, _first_video.get())));
+ shared_ptr<TimedSubtitle> ts;
+ try {
+ emit_subtitle (shared_ptr<TimedSubtitle> (new TimedSubtitle (sub)));
+ } catch (...) {
+ /* some problem with the subtitle; we probably didn't understand it */
+ }
} else {
- process_subtitle (shared_ptr<TimedSubtitle> ());
+ emit_subtitle (shared_ptr<TimedSubtitle> ());
}
avsubtitle_free (&sub);
}
return false;
}
-float
-FFmpegDecoder::frames_per_second () const
+/** @param data pointer to array of pointers to buffers.
+ * Only the first buffer will be used for non-planar data, otherwise there will be one per channel.
+ */
+shared_ptr<AudioBuffers>
+FFmpegDecoder::deinterleave_audio (uint8_t** data, int size)
{
- AVStream* s = _format_context->streams[_video_stream];
+ assert (_film->audio_channels());
+ assert (bytes_per_audio_sample());
- if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
- return av_q2d (s->avg_frame_rate);
+ shared_ptr<FFmpegAudioStream> ffa = dynamic_pointer_cast<FFmpegAudioStream> (_audio_stream);
+ assert (ffa);
+
+ /* Deinterleave and convert to float */
+
+ assert ((size % (bytes_per_audio_sample() * ffa->channels())) == 0);
+
+ int const total_samples = size / bytes_per_audio_sample();
+ int const frames = total_samples / _film->audio_channels();
+ shared_ptr<AudioBuffers> audio (new AudioBuffers (ffa->channels(), frames));
+
+ switch (audio_sample_format()) {
+ case AV_SAMPLE_FMT_S16:
+ {
+ int16_t* p = reinterpret_cast<int16_t *> (data[0]);
+ int sample = 0;
+ int channel = 0;
+ for (int i = 0; i < total_samples; ++i) {
+ audio->data(channel)[sample] = float(*p++) / (1 << 15);
+
+ ++channel;
+ if (channel == _film->audio_channels()) {
+ channel = 0;
+ ++sample;
+ }
+ }
}
+ break;
+
+ case AV_SAMPLE_FMT_S16P:
+ {
+ int16_t** p = reinterpret_cast<int16_t **> (data);
+ for (int i = 0; i < _film->audio_channels(); ++i) {
+ for (int j = 0; j < frames; ++j) {
+ audio->data(i)[j] = static_cast<float>(p[i][j]) / (1 << 15);
+ }
+ }
+ }
+ break;
+
+ case AV_SAMPLE_FMT_S32:
+ {
+ int32_t* p = reinterpret_cast<int32_t *> (data[0]);
+ int sample = 0;
+ int channel = 0;
+ for (int i = 0; i < total_samples; ++i) {
+ audio->data(channel)[sample] = static_cast<float>(*p++) / (1 << 31);
+
+ ++channel;
+ if (channel == _film->audio_channels()) {
+ channel = 0;
+ ++sample;
+ }
+ }
+ }
+ break;
+
+ case AV_SAMPLE_FMT_FLT:
+ {
+ float* p = reinterpret_cast<float*> (data[0]);
+ int sample = 0;
+ int channel = 0;
+ for (int i = 0; i < total_samples; ++i) {
+ audio->data(channel)[sample] = *p++;
+
+ ++channel;
+ if (channel == _film->audio_channels()) {
+ channel = 0;
+ ++sample;
+ }
+ }
+ }
+ break;
+
+ case AV_SAMPLE_FMT_FLTP:
+ {
+ float** p = reinterpret_cast<float**> (data);
+ for (int i = 0; i < _film->audio_channels(); ++i) {
+ memcpy (audio->data(i), p[i], frames * sizeof(float));
+ }
+ }
+ break;
- return av_q2d (s->r_frame_rate);
-}
-
-int
-FFmpegDecoder::audio_channels () const
-{
- if (_audio_codec_context == 0) {
- return 0;
+ default:
+ throw DecodeError (String::compose (_("Unrecognised audio sample format (%1)"), static_cast<int> (audio_sample_format())));
}
- return _audio_codec_context->channels;
+ return audio;
}
-int
-FFmpegDecoder::audio_sample_rate () const
+float
+FFmpegDecoder::frames_per_second () const
{
- if (_audio_codec_context == 0) {
- return 0;
+ AVStream* s = _format_context->streams[_video_stream];
+
+ if (s->avg_frame_rate.num && s->avg_frame_rate.den) {
+ return av_q2d (s->avg_frame_rate);
}
-
- return _audio_codec_context->sample_rate;
+
+ return av_q2d (s->r_frame_rate);
}
AVSampleFormat
return _audio_codec_context->sample_fmt;
}
-int64_t
-FFmpegDecoder::audio_channel_layout () const
-{
- if (_audio_codec_context == 0) {
- return 0;
- }
-
- return _audio_codec_context->channel_layout;
-}
-
-Size
+libdcp::Size
FFmpegDecoder::native_size () const
{
- return Size (_video_codec_context->width, _video_codec_context->height);
+ return libdcp::Size (_video_codec_context->width, _video_codec_context->height);
}
PixelFormat
return _video_codec_context->sample_aspect_ratio.den;
}
+string
+FFmpegDecoder::stream_name (AVStream* s) const
+{
+ stringstream n;
+
+ AVDictionaryEntry const * lang = av_dict_get (s->metadata, N_("language"), 0, 0);
+ if (lang) {
+ n << lang->value;
+ }
+
+ AVDictionaryEntry const * title = av_dict_get (s->metadata, N_("title"), 0, 0);
+ if (title) {
+ if (!n.str().empty()) {
+ n << N_(" ");
+ }
+ n << title->value;
+ }
+
+ if (n.str().empty()) {
+ n << N_("unknown");
+ }
+
+ return n.str ();
+}
+
+int
+FFmpegDecoder::bytes_per_audio_sample () const
+{
+ return av_get_bytes_per_sample (audio_sample_format ());
+}
+
+void
+FFmpegDecoder::set_audio_stream (shared_ptr<AudioStream> s)
+{
+ AudioDecoder::set_audio_stream (s);
+ setup_audio ();
+}
+
+void
+FFmpegDecoder::set_subtitle_stream (shared_ptr<SubtitleStream> s)
+{
+ VideoDecoder::set_subtitle_stream (s);
+ setup_subtitle ();
+ OutputChanged ();
+}
+
+void
+FFmpegDecoder::filter_and_emit_video (AVFrame* frame)
+{
+ boost::mutex::scoped_lock lm (_filter_graphs_mutex);
+
+ shared_ptr<FilterGraph> graph;
+
+ list<shared_ptr<FilterGraph> >::iterator i = _filter_graphs.begin();
+ while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (frame->width, frame->height), (AVPixelFormat) frame->format)) {
+ ++i;
+ }
+
+ if (i == _filter_graphs.end ()) {
+ graph.reset (new FilterGraph (_film, this, libdcp::Size (frame->width, frame->height), (AVPixelFormat) frame->format));
+ _filter_graphs.push_back (graph);
+ _film->log()->log (String::compose (N_("New graph for %1x%2, pixel format %3"), frame->width, frame->height, frame->format));
+ } else {
+ graph = *i;
+ }
+
+ list<shared_ptr<Image> > images = graph->process (frame);
+
+ for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
+ emit_video (*i, frame_time ());
+ }
+}
+
bool
-FFmpegDecoder::has_subtitles () const
+FFmpegDecoder::seek (double p)
{
- return (_subtitle_stream != -1);
+ return do_seek (p, false);
}
-vector<AudioStream>
-FFmpegDecoder::audio_streams () const
+bool
+FFmpegDecoder::seek_to_last ()
{
- return _audio_streams;
+ /* This AVSEEK_FLAG_BACKWARD in do_seek is a bit of a hack; without it, if we ask for a seek to the same place as last time
+ (used when we change decoder parameters and want to re-fetch the frame) we end up going forwards rather than
+ staying in the same place.
+ */
+ return do_seek (last_source_time(), true);
}
-vector<SubtitleStream>
-FFmpegDecoder::subtitle_streams () const
+bool
+FFmpegDecoder::do_seek (double p, bool backwards)
{
- return _subtitle_streams;
+ int64_t const vt = p / av_q2d (_format_context->streams[_video_stream]->time_base);
+
+ int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0);
+
+ avcodec_flush_buffers (_video_codec_context);
+ if (_subtitle_codec_context) {
+ avcodec_flush_buffers (_subtitle_codec_context);
+ }
+
+ return r < 0;
+}
+
+shared_ptr<FFmpegAudioStream>
+FFmpegAudioStream::create (string t, optional<int> v)
+{
+ if (!v) {
+ /* version < 1; no type in the string, and there's only FFmpeg streams anyway */
+ return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
+ }
+
+ stringstream s (t);
+ string type;
+ s >> type;
+ if (type != N_("ffmpeg")) {
+ return shared_ptr<FFmpegAudioStream> ();
+ }
+
+ return shared_ptr<FFmpegAudioStream> (new FFmpegAudioStream (t, v));
+}
+
+FFmpegAudioStream::FFmpegAudioStream (string t, optional<int> version)
+{
+ stringstream n (t);
+
+ int name_index = 4;
+ if (!version) {
+ name_index = 2;
+ int channels;
+ n >> _id >> channels;
+ _channel_layout = av_get_default_channel_layout (channels);
+ _sample_rate = 0;
+ } else {
+ string type;
+ /* Current (marked version 1) */
+ n >> type >> _id >> _sample_rate >> _channel_layout;
+ assert (type == N_("ffmpeg"));
+ }
+
+ for (int i = 0; i < name_index; ++i) {
+ size_t const s = t.find (' ');
+ if (s != string::npos) {
+ t = t.substr (s + 1);
+ }
+ }
+
+ _name = t;
}
string
-FFmpegDecoder::stream_name (AVStream* s) const
+FFmpegAudioStream::to_string () const
{
- stringstream n;
+ return String::compose (N_("ffmpeg %1 %2 %3 %4"), _id, _sample_rate, _channel_layout, _name);
+}
+
+void
+FFmpegDecoder::out_with_sync ()
+{
+ /* Where we are in the output, in seconds */
+ double const out_pts_seconds = video_frame() / frames_per_second();
- AVDictionaryEntry const * lang = av_dict_get (s->metadata, "language", 0, 0);
- if (lang) {
- n << lang->value;
+ /* Where we are in the source, in seconds */
+ double const source_pts_seconds = av_q2d (_format_context->streams[_packet.stream_index]->time_base)
+ * av_frame_get_best_effort_timestamp(_frame);
+
+ _film->log()->log (
+ String::compose (N_("Source video frame ready; source at %1, output at %2"), source_pts_seconds, out_pts_seconds),
+ Log::VERBOSE
+ );
+
+ if (!_first_video) {
+ _first_video = source_pts_seconds;
}
- AVDictionaryEntry const * title = av_dict_get (s->metadata, "title", 0, 0);
- if (title) {
- if (!n.str().empty()) {
- n << " ";
+ /* Difference between where we are and where we should be */
+ double const delta = source_pts_seconds - _first_video.get() - out_pts_seconds;
+ double const one_frame = 1 / frames_per_second();
+
+ /* Insert frames if required to get out_pts_seconds up to pts_seconds */
+ if (delta > one_frame) {
+ int const extra = rint (delta / one_frame);
+ for (int i = 0; i < extra; ++i) {
+ repeat_last_video ();
+ _film->log()->log (
+ String::compose (
+ N_("Extra video frame inserted at %1s; source frame %2, source PTS %3 (at %4 fps)"),
+ out_pts_seconds, video_frame(), source_pts_seconds, frames_per_second()
+ )
+ );
}
- n << title->value;
}
+
+ if (delta > -one_frame) {
+ /* Process this frame */
+ filter_and_emit_video (_frame);
+ } else {
+ /* Otherwise we are omitting a frame to keep things right */
+ _film->log()->log (String::compose (N_("Frame removed at %1s"), out_pts_seconds));
+ }
+}
- if (n.str().empty()) {
- n << "unknown";
+void
+FFmpegDecoder::film_changed (Film::Property p)
+{
+ switch (p) {
+ case Film::CROP:
+ case Film::FILTERS:
+ {
+ boost::mutex::scoped_lock lm (_filter_graphs_mutex);
+ _filter_graphs.clear ();
}
+ OutputChanged ();
+ break;
- return n.str ();
+ default:
+ break;
+ }
+}
+
+/** @return Length (in video frames) according to our content's header */
+SourceFrame
+FFmpegDecoder::length () const
+{
+ return (double(_format_context->duration) / AV_TIME_BASE) * frames_per_second();
+}
+
+double
+FFmpegDecoder::frame_time () const
+{
+ return av_frame_get_best_effort_timestamp(_frame) * av_q2d (_format_context->streams[_video_stream]->time_base);
}