using std::stringstream;
using std::list;
using std::min;
+using std::pair;
using boost::shared_ptr;
using boost::optional;
using boost::dynamic_pointer_cast;
FFmpegDecoder::FFmpegDecoder (shared_ptr<const Film> f, shared_ptr<const FFmpegContent> c, bool video, bool audio)
: Decoder (f)
, VideoDecoder (f)
- , AudioDecoder (f, c)
+ , AudioDecoder (f)
, SubtitleDecoder (f)
, FFmpeg (c)
, _subtitle_codec_context (0)
, _subtitle_codec (0)
, _decode_video (video)
, _decode_audio (audio)
- , _pts_offset (0)
+ , _video_pts_offset (0)
+ , _audio_pts_offset (0)
, _just_sought (false)
{
setup_subtitle ();
- if (video && audio && c->audio_stream() && c->first_video() && c->audio_stream()->first_audio) {
- _pts_offset = compute_pts_offset (c->first_video().get(), c->audio_stream()->first_audio.get(), c->video_frame_rate());
- }
-}
+ /* Audio and video frame PTS values may not start with 0. We want
+ to fiddle them so that:
-double
-FFmpegDecoder::compute_pts_offset (double first_video, double first_audio, float video_frame_rate)
-{
- double const old_first_video = first_video;
-
- /* Round the first video to a frame boundary */
- if (fabs (rint (first_video * video_frame_rate) - first_video * video_frame_rate) > 1e-6) {
- first_video = ceil (first_video * video_frame_rate) / video_frame_rate;
+ 1. One of them starts at time 0.
+ 2. The first video PTS value ends up on a frame boundary.
+
+ Then we remove big initial gaps in PTS and we allow our
+ insertion of black frames to work.
+
+ We will do:
+ audio_pts_to_use = audio_pts_from_ffmpeg + audio_pts_offset;
+ video_pts_to_use = video_pts_from_ffmpeg + video_pts_offset;
+ */
+
+ bool const have_video = video && c->first_video();
+ bool const have_audio = audio && c->audio_stream() && c->audio_stream()->first_audio;
+
+ /* First, make one of them start at 0 */
+
+ if (have_audio && have_video) {
+ _video_pts_offset = _audio_pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get());
+ } else if (have_video) {
+ _video_pts_offset = - c->first_video().get();
}
- /* Compute the required offset (also removing any common start delay) */
- return first_video - old_first_video - min (first_video, first_audio);
+ /* Now adjust both so that the video pts starts on a frame */
+ if (have_video && have_audio) {
+ double first_video = c->first_video().get() + _video_pts_offset;
+ double const old_first_video = first_video;
+
+ /* Round the first video up to a frame boundary */
+ if (fabs (rint (first_video * c->video_frame_rate()) - first_video * c->video_frame_rate()) > 1e-6) {
+ first_video = ceil (first_video * c->video_frame_rate()) / c->video_frame_rate ();
+ }
+
+ _video_pts_offset += first_video - old_first_video;
+ _audio_pts_offset += first_video - old_first_video;
+ }
}
FFmpegDecoder::~FFmpegDecoder ()
FFmpegDecoder::seek (VideoContent::Frame frame, bool accurate)
{
double const time_base = av_q2d (_format_context->streams[_video_stream]->time_base);
- int64_t const vt = frame / (_ffmpeg_content->video_frame_rate() * time_base);
- av_seek_frame (_format_context, _video_stream, vt, AVSEEK_FLAG_BACKWARD);
+
+ /* If we are doing an accurate seek, our initial shot will be 5 frames (5 being
+ a number plucked from the air) earlier than we want to end up. The loop below
+ will hopefully then step through to where we want to be.
+ */
+ int initial = frame;
+ if (accurate) {
+ initial -= 5;
+ }
+
+ if (initial < 0) {
+ initial = 0;
+ }
+
+ /* Initial seek time in the stream's timebase */
+ int64_t const initial_vt = ((initial / _ffmpeg_content->video_frame_rate()) - _video_pts_offset) / time_base;
+ /* Wanted final seek time in the stream's timebase */
+ int64_t const final_vt = ((frame / _ffmpeg_content->video_frame_rate()) - _video_pts_offset) / time_base;
+
+ av_seek_frame (_format_context, _video_stream, initial_vt, AVSEEK_FLAG_BACKWARD);
avcodec_flush_buffers (video_codec_context());
if (_subtitle_codec_context) {
int const r = avcodec_decode_video2 (video_codec_context(), _frame, &finished, &_packet);
if (r >= 0 && finished) {
int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
- if (bet >= vt) {
+ if (bet >= final_vt) {
_video_position = rint (
- (bet * time_base + _pts_offset) * _ffmpeg_content->video_frame_rate()
+ (bet * time_base + _video_pts_offset) * _ffmpeg_content->video_frame_rate()
);
av_free_packet (&_packet);
break;
if (_audio_position == 0) {
/* Where we are in the source, in seconds */
double const pts = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base)
- * av_frame_get_best_effort_timestamp(_frame) - _pts_offset;
+ * av_frame_get_best_effort_timestamp(_frame) + _audio_pts_offset;
if (pts > 0) {
/* Emit some silence */
graph = *i;
}
- list<shared_ptr<Image> > images = graph->process (_frame);
+ list<pair<shared_ptr<Image>, int64_t> > images = graph->process (_frame);
string post_process = Filter::ffmpeg_strings (_ffmpeg_content->filters()).second;
- for (list<shared_ptr<Image> >::iterator i = images.begin(); i != images.end(); ++i) {
+ for (list<pair<shared_ptr<Image>, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) {
- shared_ptr<Image> image = *i;
+ shared_ptr<Image> image = i->first;
if (!post_process.empty ()) {
image = image->post_process (post_process, true);
}
- int64_t const bet = av_frame_get_best_effort_timestamp (_frame);
- if (bet != AV_NOPTS_VALUE) {
+ if (i->second != AV_NOPTS_VALUE) {
- double const pts = bet * av_q2d (_format_context->streams[_video_stream]->time_base) - _pts_offset;
+ double const pts = i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _video_pts_offset;
if (_just_sought) {
/* We just did a seek, so disable any attempts to correct for where we
a black frame.
*/
boost::shared_ptr<Image> black (
- new SimpleImage (
+ new Image (
static_cast<AVPixelFormat> (_frame->format),
libdcp::Size (video_codec_context()->width, video_codec_context()->height),
true
throw DecodeError (_("non-bitmap subtitles not yet supported"));
}
- shared_ptr<Image> image (new SimpleImage (PIX_FMT_RGBA, libdcp::Size (rect->w, rect->h), true));
+ shared_ptr<Image> image (new Image (PIX_FMT_RGBA, libdcp::Size (rect->w, rect->h), true));
/* Start of the first line in the subtitle */
uint8_t* sub_p = rect->pict.data[0];
projects / dcpomatic.git / blobdiff