X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fffmpeg_decoder.cc;h=ea32d102d6a7aacba93720896f266bfc657a32d5;hb=39bc73fe192f932ed6695eb87b19de446e8b4f55;hp=a637160ae918228ad73c7e9aba46ce49dbdc1e7d;hpb=237a0052c60af768f4d62b00321932918b7ba4d9;p=dcpomatic.git diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc index a637160ae..d251a3744 100644 --- a/src/lib/ffmpeg_decoder.cc +++ b/src/lib/ffmpeg_decoder.cc @@ -1,7 +1,5 @@ -/* -*- c-basic-offset: 8; default-tab-width: 8; -*- */ - /* - Copyright (C) 2012 Carl Hetherington + Copyright (C) 2012-2014 Carl Hetherington This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -29,19 +27,11 @@ #include #include #include -#include +#include extern "C" { -#include #include #include -#include -#include } -#include -#include "film.h" -#include "format.h" -#include "transcoder.h" -#include "job.h" #include "filter.h" #include "exceptions.h" #include "image.h" @@ -49,8 +39,9 @@ extern "C" { #include "log.h" #include "ffmpeg_decoder.h" #include "filter_graph.h" -#include "subtitle.h" #include "audio_buffers.h" +#include "ffmpeg_content.h" +#include "image_proxy.h" #include "i18n.h" @@ -59,168 +50,83 @@ using std::string; using std::vector; using std::stringstream; using std::list; +using std::min; +using std::pair; using boost::shared_ptr; using boost::optional; using boost::dynamic_pointer_cast; -using libdcp::Size; - -boost::mutex FFmpegDecoder::_mutex; - -FFmpegDecoder::FFmpegDecoder (shared_ptr f, shared_ptr c, bool video, bool audio, bool subtitles) - : Decoder (f) - , VideoDecoder (f) - , AudioDecoder (f, c) - , _ffmpeg_content (c) - , _format_context (0) - , _video_stream (-1) - , _frame (0) - , _video_codec_context (0) - , _video_codec (0) - , _audio_codec_context (0) - , _audio_codec (0) +using dcp::Size; + +FFmpegDecoder::FFmpegDecoder (shared_ptr c, shared_ptr log) + : VideoDecoder (c) + , AudioDecoder (c) + , FFmpeg (c) + , _log (log) , _subtitle_codec_context (0) , _subtitle_codec (0) - , _decode_video (video) - , _decode_audio (audio) - , _decode_subtitles (subtitles) { - setup_general (); - setup_video (); - setup_audio (); setup_subtitle (); -} - -FFmpegDecoder::~FFmpegDecoder () -{ - boost::mutex::scoped_lock lm (_mutex); - - if (_audio_codec_context) { - avcodec_close (_audio_codec_context); - } - - if (_video_codec_context) { - avcodec_close (_video_codec_context); - } - - if (_subtitle_codec_context) { - avcodec_close (_subtitle_codec_context); - } - - av_free (_frame); - - avformat_close_input (&_format_context); -} -void -FFmpegDecoder::setup_general () -{ - av_register_all (); + /* Audio and video frame PTS values may not start with 0. We want + to fiddle them so that: - if (avformat_open_input (&_format_context, _ffmpeg_content->file().string().c_str(), 0, 0) < 0) { - throw OpenFileError (_ffmpeg_content->file().string ()); - } + 1. One of them starts at time 0. + 2. The first video PTS value ends up on a frame boundary. - if (avformat_find_stream_info (_format_context, 0) < 0) { - throw DecodeError (_("could not find stream information")); - } + Then we remove big initial gaps in PTS and we allow our + insertion of black frames to work. - /* Find video, audio and subtitle streams */ - - for (uint32_t i = 0; i < _format_context->nb_streams; ++i) { - AVStream* s = _format_context->streams[i]; - if (s->codec->codec_type == AVMEDIA_TYPE_VIDEO) { - _video_stream = i; - } else if (s->codec->codec_type == AVMEDIA_TYPE_AUDIO) { - - /* 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. - */ + We will do pts_to_use = pts_from_ffmpeg + pts_offset; + */ - if (s->codec->channel_layout == 0) { - s->codec->channel_layout = av_get_default_channel_layout (s->codec->channels); - } - - _audio_streams.push_back ( - shared_ptr ( - new FFmpegAudioStream (stream_name (s), i, s->codec->sample_rate, s->codec->channels) - ) - ); + bool const have_video = c->first_video(); + bool const have_audio = c->audio_stream () && c->audio_stream()->first_audio; - } else if (s->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) { - _subtitle_streams.push_back (shared_ptr (new FFmpegSubtitleStream (stream_name (s), i))); - } - } + /* First, make one of them start at 0 */ - if (_video_stream < 0) { - throw DecodeError (N_("could not find video stream")); + if (have_audio && have_video) { + _pts_offset = - min (c->first_video().get(), c->audio_stream()->first_audio.get()); + } else if (have_video) { + _pts_offset = - c->first_video().get(); + } else if (have_audio) { + _pts_offset = - c->audio_stream()->first_audio.get(); } - _frame = avcodec_alloc_frame (); - if (_frame == 0) { - throw DecodeError (N_("could not allocate frame")); + /* Now adjust both so that the video pts starts on a frame */ + if (have_video && have_audio) { + ContentTime first_video = c->first_video().get() + _pts_offset; + ContentTime const old_first_video = first_video; + _pts_offset += first_video.round_up (c->video_frame_rate ()) - old_first_video; } } -void -FFmpegDecoder::setup_video () +FFmpegDecoder::~FFmpegDecoder () { boost::mutex::scoped_lock lm (_mutex); - - _video_codec_context = _format_context->streams[_video_stream]->codec; - _video_codec = avcodec_find_decoder (_video_codec_context->codec_id); - - if (_video_codec == 0) { - throw DecodeError (_("could not find video decoder")); - } - if (avcodec_open2 (_video_codec_context, _video_codec, 0) < 0) { - throw DecodeError (N_("could not open video decoder")); + if (_subtitle_codec_context) { + avcodec_close (_subtitle_codec_context); } } void -FFmpegDecoder::setup_audio () +FFmpegDecoder::flush () { - boost::mutex::scoped_lock lm (_mutex); + /* Get any remaining frames */ - if (!_ffmpeg_content->audio_stream ()) { - return; - } - - _audio_codec_context = _format_context->streams[_ffmpeg_content->audio_stream()->id]->codec; - _audio_codec = avcodec_find_decoder (_audio_codec_context->codec_id); - - if (_audio_codec == 0) { - throw DecodeError (_("could not find audio decoder")); - } - - if (avcodec_open2 (_audio_codec_context, _audio_codec, 0) < 0) { - throw DecodeError (N_("could not open audio decoder")); - } -} - -void -FFmpegDecoder::setup_subtitle () -{ - boost::mutex::scoped_lock lm (_mutex); + _packet.data = 0; + _packet.size = 0; - if (!_ffmpeg_content->subtitle_stream() || _ffmpeg_content->subtitle_stream()->id >= int (_format_context->nb_streams)) { - return; - } - - _subtitle_codec_context = _format_context->streams[_ffmpeg_content->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")); - } + /* XXX: should we reset _packet.data and size after each *_decode_* call? */ - if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) { - throw DecodeError (N_("could not open subtitle decoder")); + while (decode_video_packet ()) {} + + if (_ffmpeg_content->audio_stream()) { + decode_audio_packet (); + AudioDecoder::flush (); } } - bool FFmpegDecoder::pass () { @@ -231,55 +137,23 @@ FFmpegDecoder::pass () /* 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 (N_("error on av_read_frame (%1) (%2)"), buf, r)); + _log->log (String::compose (N_("error on av_read_frame (%1) (%2)"), buf, r)); } - /* Get any remaining frames */ - - _packet.data = 0; - _packet.size = 0; - - /* XXX: should we reset _packet.data and size after each *_decode_* call? */ - - if (_decode_video) { - while (decode_video_packet ()); - } - - if (_ffmpeg_content->audio_stream() && _decode_audio) { - decode_audio_packet (); - } - + flush (); return true; } - avcodec_get_frame_defaults (_frame); - - if (_packet.stream_index == _video_stream && _decode_video) { + int const si = _packet.stream_index; + + if (si == _video_stream) { decode_video_packet (); - } else if (_ffmpeg_content->audio_stream() && _packet.stream_index == _ffmpeg_content->audio_stream()->id && _decode_audio) { + } else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, si)) { decode_audio_packet (); - } else if (_ffmpeg_content->subtitle_stream() && _packet.stream_index == _ffmpeg_content->subtitle_stream()->id && _decode_subtitles) { - - int got_subtitle; - AVSubtitle sub; - if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) && got_subtitle) { - /* Sometimes we get an empty AVSubtitle, which is used by some codecs to - indicate that the previous subtitle should stop. - */ - if (sub.num_rects > 0) { - shared_ptr ts; - try { - emit_subtitle (shared_ptr (new TimedSubtitle (sub))); - } catch (...) { - /* some problem with the subtitle; we probably didn't understand it */ - } - } else { - emit_subtitle (shared_ptr ()); - } - avsubtitle_free (&sub); - } + } else if (_ffmpeg_content->subtitle_stream() && _ffmpeg_content->subtitle_stream()->uses_index (_format_context, si)) { + decode_subtitle_packet (); } - + av_free_packet (&_packet); return false; } @@ -302,6 +176,23 @@ FFmpegDecoder::deinterleave_audio (uint8_t** data, int size) shared_ptr audio (new AudioBuffers (_ffmpeg_content->audio_channels(), frames)); switch (audio_sample_format()) { + case AV_SAMPLE_FMT_U8: + { + uint8_t* p = reinterpret_cast (data[0]); + int sample = 0; + int channel = 0; + for (int i = 0; i < total_samples; ++i) { + audio->data(channel)[sample] = float(*p++) / (1 << 23); + + ++channel; + if (channel == _ffmpeg_content->audio_channels()) { + channel = 0; + ++sample; + } + } + } + break; + case AV_SAMPLE_FMT_S16: { int16_t* p = reinterpret_cast (data[0]); @@ -380,184 +271,148 @@ FFmpegDecoder::deinterleave_audio (uint8_t** data, int size) return audio; } -float -FFmpegDecoder::video_frame_rate () const -{ - 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 av_q2d (s->r_frame_rate); -} - AVSampleFormat FFmpegDecoder::audio_sample_format () const { - if (_audio_codec_context == 0) { + if (!_ffmpeg_content->audio_stream()) { return (AVSampleFormat) 0; } - return _audio_codec_context->sample_fmt; -} - -libdcp::Size -FFmpegDecoder::native_size () const -{ - return libdcp::Size (_video_codec_context->width, _video_codec_context->height); -} - -PixelFormat -FFmpegDecoder::pixel_format () const -{ - return _video_codec_context->pix_fmt; + return audio_codec_context()->sample_fmt; } int -FFmpegDecoder::time_base_numerator () const +FFmpegDecoder::bytes_per_audio_sample () const { - return _video_codec_context->time_base.num; + return av_get_bytes_per_sample (audio_sample_format ()); } int -FFmpegDecoder::time_base_denominator () const +FFmpegDecoder::minimal_run (boost::function, optional, int)> finished) { - return _video_codec_context->time_base.den; -} + int frames_read = 0; + optional last_video; + optional last_audio; + + while (!finished (last_video, last_audio, frames_read)) { + int r = av_read_frame (_format_context, &_packet); + if (r < 0) { + /* We should flush our decoders here, possibly yielding a few more frames, + but the consequence of having to do that is too hideous to contemplate. + Instead we give up and say that you can't seek too close to the end + of a file. + */ + return frames_read; + } -int -FFmpegDecoder::sample_aspect_ratio_numerator () const -{ - return _video_codec_context->sample_aspect_ratio.num; -} + ++frames_read; -int -FFmpegDecoder::sample_aspect_ratio_denominator () const -{ - return _video_codec_context->sample_aspect_ratio.den; -} + double const time_base = av_q2d (_format_context->streams[_packet.stream_index]->time_base); -string -FFmpegDecoder::stream_name (AVStream* s) const -{ - stringstream n; + if (_packet.stream_index == _video_stream) { - if (s->metadata) { - 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_(" "); + avcodec_get_frame_defaults (_frame); + + int got_picture = 0; + r = avcodec_decode_video2 (video_codec_context(), _frame, &got_picture, &_packet); + if (r >= 0 && got_picture) { + last_video = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base) + _pts_offset; } - n << title->value; - } - } - if (n.str().empty()) { - n << N_("unknown"); - } + } else if (_ffmpeg_content->audio_stream() && _ffmpeg_content->audio_stream()->uses_index (_format_context, _packet.stream_index)) { + AVPacket copy_packet = _packet; + while (copy_packet.size > 0) { - return n.str (); -} + int got_frame; + r = avcodec_decode_audio4 (audio_codec_context(), _frame, &got_frame, &_packet); + if (r >= 0 && got_frame) { + last_audio = ContentTime::from_seconds (av_frame_get_best_effort_timestamp (_frame) * time_base) + _pts_offset; + } + + copy_packet.data += r; + copy_packet.size -= r; + } + } + + av_free_packet (&_packet); + } -int -FFmpegDecoder::bytes_per_audio_sample () const -{ - return av_get_bytes_per_sample (audio_sample_format ()); + return frames_read; } bool -FFmpegDecoder::seek (double p) +FFmpegDecoder::seek_overrun_finished (ContentTime seek, optional last_video, optional last_audio) const { - return do_seek (p, false, false); + return (last_video && last_video.get() >= seek) || (last_audio && last_audio.get() >= seek); } bool -FFmpegDecoder::seek_back () +FFmpegDecoder::seek_final_finished (int n, int done) const { - if (last_content_time() < 2.5) { - return true; - } - - return do_seek (last_content_time() - 2.5 / video_frame_rate(), true, true); + return n == done; } -bool -FFmpegDecoder::seek_forward () +void +FFmpegDecoder::seek_and_flush (ContentTime t) { - if (last_content_time() >= (video_length() - video_frame_rate())) { - return true; + ContentTime const u = t - _pts_offset; + int64_t s = u.seconds() / av_q2d (_format_context->streams[_video_stream]->time_base); + + if (_ffmpeg_content->audio_stream ()) { + s = min ( + s, int64_t (u.seconds() / av_q2d (_ffmpeg_content->audio_stream()->stream(_format_context)->time_base)) + ); } - - return do_seek (last_content_time() - 0.5 / video_frame_rate(), true, true); -} -bool -FFmpegDecoder::do_seek (double p, bool backwards, bool accurate) -{ - int64_t const vt = p / av_q2d (_format_context->streams[_video_stream]->time_base); + /* Ridiculous empirical hack */ + s--; + if (s < 0) { + s = 0; + } - int const r = av_seek_frame (_format_context, _video_stream, vt, backwards ? AVSEEK_FLAG_BACKWARD : 0); + av_seek_frame (_format_context, _video_stream, s, 0); - avcodec_flush_buffers (_video_codec_context); + avcodec_flush_buffers (video_codec_context()); + if (audio_codec_context ()) { + avcodec_flush_buffers (audio_codec_context ()); + } if (_subtitle_codec_context) { avcodec_flush_buffers (_subtitle_codec_context); } - - if (accurate) { - while (1) { - int r = av_read_frame (_format_context, &_packet); - if (r < 0) { - return true; - } - - avcodec_get_frame_defaults (_frame); - - if (_packet.stream_index == _video_stream) { - int finished = 0; - 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) { - break; - } - } - } - - av_free_packet (&_packet); - } - } - - return r < 0; } void -FFmpegDecoder::film_changed (Film::Property p) +FFmpegDecoder::seek (ContentTime time, bool accurate) { - switch (p) { - case Film::CROP: - case Film::FILTERS: - { - boost::mutex::scoped_lock lm (_filter_graphs_mutex); - _filter_graphs.clear (); + VideoDecoder::seek (time, accurate); + AudioDecoder::seek (time, accurate); + + /* If we are doing an accurate seek, our initial shot will be 2s (2 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. + */ + + ContentTime pre_roll = accurate ? ContentTime::from_seconds (2) : ContentTime (0); + ContentTime initial_seek = time - pre_roll; + if (initial_seek < ContentTime (0)) { + initial_seek = ContentTime (0); } - break; - default: - break; + /* Initial seek time in the video stream's timebase */ + + seek_and_flush (initial_seek); + + if (!accurate) { + /* That'll do */ + return; } -} -/** @return Length (in video frames) according to our content's header */ -ContentVideoFrame -FFmpegDecoder::video_length () const -{ - return (double(_format_context->duration) / AV_TIME_BASE) * video_frame_rate(); + int const N = minimal_run (boost::bind (&FFmpegDecoder::seek_overrun_finished, this, time, _1, _2)); + + seek_and_flush (initial_seek); + if (N > 0) { + minimal_run (boost::bind (&FFmpegDecoder::seek_final_finished, this, N - 1, _3)); + } } void @@ -568,29 +423,32 @@ FFmpegDecoder::decode_audio_packet () */ AVPacket copy_packet = _packet; - + while (copy_packet.size > 0) { int frame_finished; - int const decode_result = avcodec_decode_audio4 (_audio_codec_context, _frame, &frame_finished, ©_packet); - if (decode_result >= 0) { - if (frame_finished) { - - /* Where we are in the source, in seconds */ - double const source_pts_seconds = av_q2d (_format_context->streams[copy_packet.stream_index]->time_base) - * av_frame_get_best_effort_timestamp(_frame); - - 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 == _ffmpeg_content->audio_channels()); - Audio (deinterleave_audio (_frame->data, data_size), source_pts_seconds); - } + int const decode_result = avcodec_decode_audio4 (audio_codec_context(), _frame, &frame_finished, ©_packet); + + if (decode_result < 0) { + _log->log (String::compose ("avcodec_decode_audio4 failed (%1)", decode_result)); + return; + } + + if (frame_finished) { + ContentTime const ct = ContentTime::from_seconds ( + av_frame_get_best_effort_timestamp (_frame) * + av_q2d (_ffmpeg_content->audio_stream()->stream (_format_context)->time_base)) + + _pts_offset; - copy_packet.data += decode_result; - copy_packet.size -= decode_result; + int const data_size = av_samples_get_buffer_size ( + 0, audio_codec_context()->channels, _frame->nb_samples, audio_sample_format (), 1 + ); + + audio (deinterleave_audio (_frame->data, data_size), ct); } + + copy_packet.data += decode_result; + copy_packet.size -= decode_result; } } @@ -598,40 +456,144 @@ bool FFmpegDecoder::decode_video_packet () { int frame_finished; - if (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) < 0 || !frame_finished) { + if (avcodec_decode_video2 (video_codec_context(), _frame, &frame_finished, &_packet) < 0 || !frame_finished) { return false; } - + boost::mutex::scoped_lock lm (_filter_graphs_mutex); - + shared_ptr graph; list >::iterator i = _filter_graphs.begin(); - while (i != _filter_graphs.end() && !(*i)->can_process (libdcp::Size (_frame->width, _frame->height), (AVPixelFormat) _frame->format)) { + while (i != _filter_graphs.end() && !(*i)->can_process (dcp::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)); + graph.reset (new FilterGraph (_ffmpeg_content, dcp::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)); + _log->log (String::compose (N_("New graph for %1x%2, pixel format %3"), _frame->width, _frame->height, _frame->format)); } else { graph = *i; } - - list > images = graph->process (_frame); - - for (list >::iterator i = images.begin(); i != images.end(); ++i) { - int64_t const bet = av_frame_get_best_effort_timestamp (_frame); - if (bet != AV_NOPTS_VALUE) { - /* XXX: may need to insert extra frames / remove frames here ... - (as per old Matcher) - */ - emit_video (*i, false, bet * av_q2d (_format_context->streams[_video_stream]->time_base) * TIME_HZ); + + list, int64_t> > images = graph->process (_frame); + + for (list, int64_t> >::iterator i = images.begin(); i != images.end(); ++i) { + + shared_ptr image = i->first; + + if (i->second != AV_NOPTS_VALUE) { + double const pts = i->second * av_q2d (_format_context->streams[_video_stream]->time_base) + _pts_offset.seconds (); + video (shared_ptr (new RawImageProxy (image)), rint (pts * _ffmpeg_content->video_frame_rate ())); } else { - _film->log()->log ("Dropping frame without PTS"); + _log->log ("Dropping frame without PTS"); } } return true; } + + +void +FFmpegDecoder::setup_subtitle () +{ + boost::mutex::scoped_lock lm (_mutex); + + if (!_ffmpeg_content->subtitle_stream()) { + return; + } + + _subtitle_codec_context = _ffmpeg_content->subtitle_stream()->stream(_format_context)->codec; + if (_subtitle_codec_context == 0) { + throw DecodeError (N_("could not find subtitle stream")); + } + + _subtitle_codec = avcodec_find_decoder (_subtitle_codec_context->codec_id); + + if (_subtitle_codec == 0) { + throw DecodeError (N_("could not find subtitle decoder")); + } + + if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) { + throw DecodeError (N_("could not open subtitle decoder")); + } +} + +void +FFmpegDecoder::decode_subtitle_packet () +{ + int got_subtitle; + AVSubtitle sub; + if (avcodec_decode_subtitle2 (_subtitle_codec_context, &sub, &got_subtitle, &_packet) < 0 || !got_subtitle) { + return; + } + + /* Sometimes we get an empty AVSubtitle, which is used by some codecs to + indicate that the previous subtitle should stop. + */ + if (sub.num_rects <= 0) { + image_subtitle (ContentTime (), ContentTime (), shared_ptr (), dcpomatic::Rect ()); + return; + } else if (sub.num_rects > 1) { + throw DecodeError (_("multi-part subtitles not yet supported")); + } + + /* Subtitle PTS (within the source, not taking into account any of the + source that we may have chopped off for the DCP) + */ + ContentTime packet_time = ContentTime::from_seconds (static_cast (sub.pts) / AV_TIME_BASE) + _pts_offset; + + /* hence start time for this sub */ + ContentTime const from = packet_time + ContentTime::from_seconds (sub.start_display_time / 1e3); + ContentTime const to = packet_time + ContentTime::from_seconds (sub.end_display_time / 1e3); + + AVSubtitleRect const * rect = sub.rects[0]; + + if (rect->type != SUBTITLE_BITMAP) { + /* XXX */ + // throw DecodeError (_("non-bitmap subtitles not yet supported")); + return; + } + + /* Note RGBA is expressed little-endian, so the first byte in the word is R, second + G, third B, fourth A. + */ + shared_ptr image (new Image (PIX_FMT_RGBA, dcp::Size (rect->w, rect->h), true)); + + /* Start of the first line in the subtitle */ + uint8_t* sub_p = rect->pict.data[0]; + /* sub_p looks up into a BGRA palette which is here + (i.e. first byte B, second G, third R, fourth A) + */ + uint32_t const * palette = (uint32_t *) rect->pict.data[1]; + /* Start of the output data */ + uint32_t* out_p = (uint32_t *) image->data()[0]; + + for (int y = 0; y < rect->h; ++y) { + uint8_t* sub_line_p = sub_p; + uint32_t* out_line_p = out_p; + for (int x = 0; x < rect->w; ++x) { + uint32_t const p = palette[*sub_line_p++]; + *out_line_p++ = ((p & 0xff) << 16) | (p & 0xff00) | ((p & 0xff0000) >> 16) | (p & 0xff000000); + } + sub_p += rect->pict.linesize[0]; + out_p += image->stride()[0] / sizeof (uint32_t); + } + + dcp::Size const vs = _ffmpeg_content->video_size (); + + image_subtitle ( + from, + to, + image, + dcpomatic::Rect ( + static_cast (rect->x) / vs.width, + static_cast (rect->y) / vs.height, + static_cast (rect->w) / vs.width, + static_cast (rect->h) / vs.height + ) + ); + + avsubtitle_free (&sub); +}