+
+
+void
+FFmpegDecoder::setup_subtitle ()
+{
+ boost::mutex::scoped_lock lm (_mutex);
+
+ 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"));
+ }
+
+ if (avcodec_open2 (_subtitle_codec_context, _subtitle_codec, 0) < 0) {
+ throw DecodeError (N_("could not open subtitle decoder"));
+ }
+}
+
+bool
+FFmpegDecoder::done () const
+{
+ bool const vd = !_decode_video || (_video_position >= _ffmpeg_content->video_length());
+ bool const ad = !_decode_audio || !_ffmpeg_content->audio_stream() || (_audio_position >= _ffmpeg_content->audio_length());
+ return vd && ad;
+}
+
+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) {
+ subtitle (shared_ptr<Image> (), dcpomatic::Rect<double> (), 0, 0);
+ return;
+ } else if (sub.num_rects > 1) {
+ throw DecodeError (_("multi-part subtitles not yet supported"));
+ }
+
+ /* Subtitle PTS in seconds (within the source, not taking into account any of the
+ source that we may have chopped off for the DCP)
+ */
+ double const packet_time = static_cast<double> (sub.pts) / AV_TIME_BASE;
+
+ /* hence start time for this sub */
+ Time const from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
+ Time const to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
+
+ AVSubtitleRect const * rect = sub.rects[0];
+
+ if (rect->type != SUBTITLE_BITMAP) {
+ throw DecodeError (_("non-bitmap subtitles not yet supported"));
+ }
+
+ 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];
+ /* sub_p looks up into a RGB palette which is here */
+ 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) {
+ *out_line_p++ = palette[*sub_line_p++];
+ }
+ sub_p += rect->pict.linesize[0];
+ out_p += image->stride()[0] / sizeof (uint32_t);
+ }
+
+ libdcp::Size const vs = _ffmpeg_content->video_size ();
+
+ subtitle (
+ image,
+ dcpomatic::Rect<double> (
+ static_cast<double> (rect->x) / vs.width,
+ static_cast<double> (rect->y) / vs.height,
+ static_cast<double> (rect->w) / vs.width,
+ static_cast<double> (rect->h) / vs.height
+ ),
+ from,
+ to
+ );
+
+
+ avsubtitle_free (&sub);
+}