+#endif
+
+#if CONFIG_SUBTITLES_FILTER
+
+#define subtitles_options options
+AVFILTER_DEFINE_CLASS(subtitles);
+
+static av_cold int init_subtitles(AVFilterContext *ctx, const char *args)
+{
+ int ret, sid;
+ AVFormatContext *fmt = NULL;
+ AVCodecContext *dec_ctx = NULL;
+ AVCodec *dec = NULL;
+ AVStream *st;
+ AVPacket pkt;
+ AssContext *ass = ctx->priv;
+
+ /* Init libass */
+ ret = init(ctx, args, &subtitles_class);
+ if (ret < 0)
+ return ret;
+ ass->track = ass_new_track(ass->library);
+ if (!ass->track) {
+ av_log(ctx, AV_LOG_ERROR, "Could not create a libass track\n");
+ return AVERROR(EINVAL);
+ }
+
+ /* Open subtitles file */
+ ret = avformat_open_input(&fmt, ass->filename, NULL, NULL);
+ if (ret < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Unable to open %s\n", ass->filename);
+ goto end;
+ }
+ ret = avformat_find_stream_info(fmt, NULL);
+ if (ret < 0)
+ goto end;
+
+ /* Locate subtitles stream */
+ ret = av_find_best_stream(fmt, AVMEDIA_TYPE_SUBTITLE, -1, -1, NULL, 0);
+ if (ret < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Unable to locate subtitle stream in %s\n",
+ ass->filename);
+ goto end;
+ }
+ sid = ret;
+ st = fmt->streams[sid];
+
+ /* Open decoder */
+ dec_ctx = st->codec;
+ dec = avcodec_find_decoder(dec_ctx->codec_id);
+ if (!dec) {
+ av_log(ctx, AV_LOG_ERROR, "Failed to find subtitle codec %s\n",
+ avcodec_get_name(dec_ctx->codec_id));
+ return AVERROR(EINVAL);
+ }
+ ret = avcodec_open2(dec_ctx, dec, NULL);
+ if (ret < 0)
+ goto end;
+
+ /* Decode subtitles and push them into the renderer (libass) */
+ if (dec_ctx->subtitle_header)
+ ass_process_codec_private(ass->track,
+ dec_ctx->subtitle_header,
+ dec_ctx->subtitle_header_size);
+ av_init_packet(&pkt);
+ pkt.data = NULL;
+ pkt.size = 0;
+ while (av_read_frame(fmt, &pkt) >= 0) {
+ int i, got_subtitle;
+ AVSubtitle sub;
+
+ if (pkt.stream_index == sid) {
+ ret = avcodec_decode_subtitle2(dec_ctx, &sub, &got_subtitle, &pkt);
+ if (ret < 0 || !got_subtitle)
+ break;
+ for (i = 0; i < sub.num_rects; i++) {
+ char *ass_line = sub.rects[i]->ass;
+ if (!ass_line)
+ break;
+ ass_process_data(ass->track, ass_line, strlen(ass_line));
+ }
+ }
+ av_free_packet(&pkt);
+ avsubtitle_free(&sub);
+ }
+
+end:
+ if (dec_ctx)
+ avcodec_close(dec_ctx);
+ if (fmt)
+ avformat_close_input(&fmt);
+ return ret;
+}
+
+AVFilter avfilter_vf_subtitles = {
+ .name = "subtitles",
+ .description = NULL_IF_CONFIG_SMALL("Render subtitles onto input video using the libass library."),
+ .priv_size = sizeof(AssContext),
+ .init = init_subtitles,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = ass_inputs,
+ .outputs = ass_outputs,
+ .priv_class = &subtitles_class,
+};
+#endif