/* * Return * - 0 -- one packet was read and processed * - AVERROR(EAGAIN) -- no packets were available for selected file, * this function should be called again * - AVERROR_EOF -- this function should not be called again */ static int process_input(int file_index) { InputFile *ifile = input_files[file_index]; AVFormatContext *is; InputStream *ist; AVPacket pkt; int ret, i, j; is = ifile->ctx; // ****<< Capture a frame: audio/video/subtitle ret = get_input_packet(ifile, &pkt); // ****<< Call stack: av_read_frame() --> read_frame_internal() --> ff_read_packet() --> s->iformat->read_packet(s, pkt); --> dshow_read_frame(); if (ret == AVERROR(EAGAIN)) { ifile->eagain = 1; return ret; } if (ret < 0) { if (ret != AVERROR_EOF) { print_error(is->filename, ret); if (exit_on_error) exit_program(1); } ifile->eof_reached = 1; for (i = 0; i < ifile->nb_streams; i++) { ist = input_streams[ifile->ist_index + i]; if (ist->decoding_needed) output_packet(ist, NULL); /* mark all outputs that don't go through lavfi as finished */ for (j = 0; j < nb_output_streams; j++) { OutputStream *ost = output_streams[j]; if (ost->source_index == ifile->ist_index + i && (ost->stream_copy || ost->enc->type == AVMEDIA_TYPE_SUBTITLE)) close_output_stream(ost); } } return AVERROR(EAGAIN); } reset_eagain(); if (do_pkt_dump) { av_pkt_dump_log2(NULL, AV_LOG_DEBUG, &pkt, do_hex_dump, is->streams[pkt.stream_index]); } /* the following test is needed in case new streams appear dynamically in stream : we ignore them */ if (pkt.stream_index >= ifile->nb_streams) { report_new_stream(file_index, &pkt); goto discard_packet; } ist = input_streams[ifile->ist_index + pkt.stream_index]; ist->data_size += pkt.size; ist->nb_packets++; if (ist->discard) goto discard_packet; if (debug_ts) { av_log(NULL, AV_LOG_INFO, "demuxer -> ist_index:%d type:%s " "next_dts:%s next_dts_time:%s next_pts:%s next_pts_time:%s pkt_pts:%s pkt_pts_time:%s pkt_dts:%s pkt_dts_time:%s off:%s off_time:%s\n", ifile->ist_index + pkt.stream_index, av_get_media_type_string(ist->dec_ctx->codec_type), av_ts2str(ist->next_dts), av_ts2timestr(ist->next_dts, &AV_TIME_BASE_Q), av_ts2str(ist->next_pts), av_ts2timestr(ist->next_pts, &AV_TIME_BASE_Q), av_ts2str(pkt.pts), av_ts2timestr(pkt.pts, &ist->st->time_base), av_ts2str(pkt.dts), av_ts2timestr(pkt.dts, &ist->st->time_base), av_ts2str(input_files[ist->file_index]->ts_offset), av_ts2timestr(input_files[ist->file_index]->ts_offset, &AV_TIME_BASE_Q)); } if(!ist->wrap_correction_done && is->start_time != AV_NOPTS_VALUE && ist->st->pts_wrap_bits < 64) { int64_t stime, stime2; // Correcting starttime based on the enabled streams // FIXME this ideally should be done before the first use of starttime but we do not know which are the enabled streams at that point. // so we instead do it here as part of discontinuity handling if ( ist->next_dts == AV_NOPTS_VALUE && ifile->ts_offset == -is->start_time && (is->iformat->flags & AVFMT_TS_DISCONT)) { int64_t new_start_time = INT64_MAX; for (i=0; i<is->nb_streams; i++) { AVStream *st = is->streams[i]; if(st->discard == AVDISCARD_ALL || st->start_time == AV_NOPTS_VALUE) continue; new_start_time = FFMIN(new_start_time, av_rescale_q(st->start_time, st->time_base, AV_TIME_BASE_Q)); } if (new_start_time > is->start_time) { av_log(is, AV_LOG_VERBOSE, "Correcting start time by %"PRId64"\n", new_start_time - is->start_time); ifile->ts_offset = -new_start_time; } } stime = av_rescale_q(is->start_time, AV_TIME_BASE_Q, ist->st->time_base); stime2= stime + (1ULL<<ist->st->pts_wrap_bits); ist->wrap_correction_done = 1; if(stime2 > stime && pkt.dts != AV_NOPTS_VALUE && pkt.dts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) { pkt.dts -= 1ULL<<ist->st->pts_wrap_bits; ist->wrap_correction_done = 0; } if(stime2 > stime && pkt.pts != AV_NOPTS_VALUE && pkt.pts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) { pkt.pts -= 1ULL<<ist->st->pts_wrap_bits; ist->wrap_correction_done = 0; } } /* add the stream-global side data to the first packet */ if (ist->nb_packets == 1) if (ist->st->nb_side_data) av_packet_split_side_data(&pkt); for (i = 0; i < ist->st->nb_side_data; i++) { AVPacketSideData *src_sd = &ist->st->side_data[i]; uint8_t *dst_data; if (av_packet_get_side_data(&pkt, src_sd->type, NULL)) continue; dst_data = av_packet_new_side_data(&pkt, src_sd->type, src_sd->size); if (!dst_data) exit_program(1); memcpy(dst_data, src_sd->data, src_sd->size); } // ****<< pkt.pts: 采集时间戳(以毫秒为单位; 一般为系统时间) // ****<< ts_offset: 起始时间戳(以毫秒为单位; 一般为第一帧采集时间戳的相反数) // ****<< 最终.pts: 相对时间戳(以毫秒为单位; 从第一帧到现在的相对时间) if (pkt.dts != AV_NOPTS_VALUE) pkt.dts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base); if (pkt.pts != AV_NOPTS_VALUE) pkt.pts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base); if (pkt.pts != AV_NOPTS_VALUE) pkt.pts *= ist->ts_scale; if (pkt.dts != AV_NOPTS_VALUE) pkt.dts *= ist->ts_scale; if (pkt.dts != AV_NOPTS_VALUE && ist->next_dts == AV_NOPTS_VALUE && !copy_ts && (is->iformat->flags & AVFMT_TS_DISCONT) && ifile->last_ts != AV_NOPTS_VALUE) { int64_t pkt_dts = av_rescale_q(pkt.dts, ist->st->time_base, AV_TIME_BASE_Q); int64_t delta = pkt_dts - ifile->last_ts; if(delta < -1LL*dts_delta_threshold*AV_TIME_BASE || (delta > 1LL*dts_delta_threshold*AV_TIME_BASE && ist->dec_ctx->codec_type != AVMEDIA_TYPE_SUBTITLE)) { ifile->ts_offset -= delta; av_log(NULL, AV_LOG_DEBUG, "Inter stream timestamp discontinuity %"PRId64", new offset= %"PRId64"\n", delta, ifile->ts_offset); pkt.dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base); if (pkt.pts != AV_NOPTS_VALUE) pkt.pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base); } } if (pkt.dts != AV_NOPTS_VALUE && ist->next_dts != AV_NOPTS_VALUE && !copy_ts) { int64_t pkt_dts = av_rescale_q(pkt.dts, ist->st->time_base, AV_TIME_BASE_Q); int64_t delta = pkt_dts - ist->next_dts; if (is->iformat->flags & AVFMT_TS_DISCONT) { if (delta < -1LL*dts_delta_threshold*AV_TIME_BASE || (delta > 1LL*dts_delta_threshold*AV_TIME_BASE && ist->dec_ctx->codec_type != AVMEDIA_TYPE_SUBTITLE) || pkt_dts + AV_TIME_BASE/10 < FFMAX(ist->pts, ist->dts)) { ifile->ts_offset -= delta; av_log(NULL, AV_LOG_DEBUG, "timestamp discontinuity %"PRId64", new offset= %"PRId64"\n", delta, ifile->ts_offset); pkt.dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base); if (pkt.pts != AV_NOPTS_VALUE) pkt.pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base); } } else { if ( delta < -1LL*dts_error_threshold*AV_TIME_BASE || (delta > 1LL*dts_error_threshold*AV_TIME_BASE && ist->dec_ctx->codec_type != AVMEDIA_TYPE_SUBTITLE)) { av_log(NULL, AV_LOG_WARNING, "DTS %"PRId64", next:%"PRId64" st:%d invalid dropping\n", pkt.dts, ist->next_dts, pkt.stream_index); pkt.dts = AV_NOPTS_VALUE; } if (pkt.pts != AV_NOPTS_VALUE) { int64_t pkt_pts = av_rescale_q(pkt.pts, ist->st->time_base, AV_TIME_BASE_Q); delta = pkt_pts - ist->next_dts; if ( delta < -1LL*dts_error_threshold*AV_TIME_BASE || (delta > 1LL*dts_error_threshold*AV_TIME_BASE && ist->dec_ctx->codec_type != AVMEDIA_TYPE_SUBTITLE)) { av_log(NULL, AV_LOG_WARNING, "PTS %"PRId64", next:%"PRId64" invalid dropping st:%d\n", pkt.pts, ist->next_dts, pkt.stream_index); pkt.pts = AV_NOPTS_VALUE; } } } } if (pkt.dts != AV_NOPTS_VALUE) ifile->last_ts = av_rescale_q(pkt.dts, ist->st->time_base, AV_TIME_BASE_Q); if (debug_ts) { av_log(NULL, AV_LOG_INFO, "demuxer+ffmpeg -> ist_index:%d type:%s pkt_pts:%s pkt_pts_time:%s pkt_dts:%s pkt_dts_time:%s off:%s off_time:%s\n", ifile->ist_index + pkt.stream_index, av_get_media_type_string(ist->dec_ctx->codec_type), av_ts2str(pkt.pts), av_ts2timestr(pkt.pts, &ist->st->time_base), av_ts2str(pkt.dts), av_ts2timestr(pkt.dts, &ist->st->time_base), av_ts2str(input_files[ist->file_index]->ts_offset), av_ts2timestr(input_files[ist->file_index]->ts_offset, &AV_TIME_BASE_Q)); } sub2video_heartbeat(ist, pkt.pts); ret = output_packet(ist, &pkt); // ****<< see output_packet.c if (ret < 0) { av_log(NULL, AV_LOG_ERROR, "Error while decoding stream #%d:%d: %s\n", ist->file_index, ist->st->index, av_err2str(ret)); if (exit_on_error) exit_program(1); } discard_packet: av_free_packet(&pkt); return 0; }
static bool write_fixed_files() { int cur_input,cur_output; unsigned long bytes_have,bytes_needed,bytes_to_xfer; char outfilename[FILENAME_SIZE]; bool success; progress_info proginfo; success = FALSE; cur_input = cur_output = 0; bytes_have = (unsigned long)files[cur_input]->data_size; bytes_needed = (unsigned long)files[cur_output]->new_data_size; proginfo.initialized = FALSE; proginfo.prefix = "Fixing"; proginfo.clause = "-->"; proginfo.filename1 = files[0]->filename; proginfo.filedesc1 = files[0]->m_ss; proginfo.filename2 = NULL; proginfo.filedesc2 = NULL; proginfo.bytes_total = 1; if (!open_this_file(cur_output,outfilename,&proginfo)) goto cleanup; if (!reopen_input_file(cur_input,&proginfo)) goto cleanup; while (cur_input < numfiles && cur_output < numfiles) { bytes_to_xfer = min(bytes_have,bytes_needed); if (transfer_n_bytes(files[cur_input]->input,files[cur_output]->output,bytes_to_xfer,&proginfo) != bytes_to_xfer) { prog_error(&proginfo); st_warning("error while transferring %lu bytes of data",bytes_to_xfer); goto cleanup; } bytes_have -= bytes_to_xfer; bytes_needed -= bytes_to_xfer; if (0 == bytes_have) { close_input_stream(files[cur_input]); files[cur_input]->input = NULL; cur_input++; if (cur_input < numfiles) { bytes_have = (unsigned long)files[cur_input]->data_size; if (!reopen_input_file(cur_input,&proginfo)) goto cleanup; } } if (0 == bytes_needed) { prog_success(&proginfo); if (numfiles - 1 == cur_output) { if (pad) { if (pad_bytes) { if (pad_bytes != write_padding(files[cur_output]->output,pad_bytes,NULL)) { prog_error(&proginfo); st_warning("error while padding with %d zero-bytes",pad_bytes); goto cleanup; } st_info("Padded last file with %d zero-bytes.\n",pad_bytes); } else st_info("No padding needed.\n"); } else { st_info("Last file was not padded, "); if (pad_bytes) st_info("though it needs %d bytes of padding.\n",pad_bytes); else st_info("nor was it needed.\n"); if ((files[cur_output]->new_data_size & 1) && (1 != write_padding(files[cur_output]->output,1,NULL))) { prog_error(&proginfo); st_warning("error while NULL-padding odd-sized data chunk"); goto cleanup; } } } close_output_stream(files[cur_output]); files[cur_output]->output = NULL; cur_output++; if (cur_output < numfiles) { bytes_needed = (unsigned long)files[cur_output]->new_data_size; if (!open_this_file(cur_output,outfilename,&proginfo)) goto cleanup; } } } success = TRUE; cleanup: if (!success) { close_output_stream(files[cur_output]); remove_file(outfilename); st_error("failed to fix files"); } return success; }