static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt) { TeletextContext *ctx = avctx->priv_data; AVSubtitle *sub = data; int ret = 0; if (!ctx->vbi) { if (!(ctx->vbi = vbi_decoder_new())) return AVERROR(ENOMEM); if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) { vbi_decoder_delete(ctx->vbi); ctx->vbi = NULL; return AVERROR(ENOMEM); } } if (avctx->pkt_timebase.den && pkt->pts != AV_NOPTS_VALUE) ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q); if (pkt->size) { int lines; const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */ // We allow unreasonably big packets, even if the standard only allows a max size of 1472 if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0) return AVERROR_INVALIDDATA; ctx->handler_ret = pkt->size; if (data_identifier_is_teletext(*pkt->data)) { if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0) return lines; av_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n", ctx, pkt->size, lines, (double)pkt->pts/90000.0); if (lines > 0) { #ifdef DEBUG int i; av_log(avctx, AV_LOG_DEBUG, "line numbers:"); for(i = 0; i < lines; i++) av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line); av_log(avctx, AV_LOG_DEBUG, "\n"); #endif vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0); ctx->lines_processed += lines; } } ctx->pts = AV_NOPTS_VALUE; ret = ctx->handler_ret; } if (ret < 0) return ret; // is there a subtitle to pass? if (ctx->nb_pages) { int i; sub->format = ctx->format_id; sub->start_display_time = 0; sub->end_display_time = ctx->sub_duration; sub->num_rects = 0; sub->pts = ctx->pages->pts; if (ctx->pages->sub_rect->type != SUBTITLE_NONE) { sub->rects = av_malloc(sizeof(*sub->rects)); if (sub->rects) { sub->num_rects = 1; sub->rects[0] = ctx->pages->sub_rect; } else { ret = AVERROR(ENOMEM); } } else { av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n"); sub->rects = NULL; } if (!sub->rects) // no rect was passed subtitle_rect_free(&ctx->pages->sub_rect); for (i = 0; i < ctx->nb_pages - 1; i++) ctx->pages[i] = ctx->pages[i + 1]; ctx->nb_pages--; if (ret >= 0) *data_size = 1; } else *data_size = 0; return ret; }