ffmpeg.c

来自「FFmpeg是用于录制、转换和流化音频和视频的完整解决方案」· C语言 代码 · 共 1,804 行 · 第 1/5 页

        nb_ostreams += os->nb_streams;
    }
    if (nb_stream_maps > 0 && nb_stream_maps != nb_ostreams) {
        fprintf(stderr, "Number of stream maps must match number of output streams\n");
        exit(1);
    }

    /* Sanity check the mapping args -- do the input files & streams exist? */
    for(i=0;i<nb_stream_maps;i++) {
        int fi = stream_maps[i].file_index;
        int si = stream_maps[i].stream_index;
        
        if (fi < 0 || fi > nb_input_files - 1 ||
            si < 0 || si > file_table[fi].nb_streams - 1) {
            fprintf(stderr,"Could not find input stream #%d.%d\n", fi, si);
            exit(1);
        }
    }
    
    ost_table = av_mallocz(sizeof(AVOutputStream *) * nb_ostreams);
    if (!ost_table)
        goto fail;
    for(i=0;i<nb_ostreams;i++) {
        ost = av_mallocz(sizeof(AVOutputStream));
        if (!ost)
            goto fail;
        ost_table[i] = ost;
    }
    
    n = 0;
    for(k=0;k<nb_output_files;k++) {
        os = output_files[k];
        for(i=0;i<os->nb_streams;i++) {
            int found;
            ost = ost_table[n++];
            ost->file_index = k;
            ost->index = i;
            ost->st = os->streams[i];
            if (nb_stream_maps > 0) {
                ost->source_index = file_table[stream_maps[n-1].file_index].ist_index + 
                    stream_maps[n-1].stream_index;
                    
                /* Sanity check that the stream types match */
                if (ist_table[ost->source_index]->st->codec.codec_type != ost->st->codec.codec_type) {
                    fprintf(stderr, "Codec type mismatch for mapping #%d.%d -> #%d.%d\n",
                        stream_maps[n-1].file_index, stream_maps[n-1].stream_index,
                        ost->file_index, ost->index);
                    exit(1);
                }
                
            } else {
                /* get corresponding input stream index : we select the first one with the right type */
                found = 0;
                for(j=0;j<nb_istreams;j++) {
                    ist = ist_table[j];
                    if (ist->discard && 
                        ist->st->codec.codec_type == ost->st->codec.codec_type) {
                        ost->source_index = j;
                        found = 1;
                        break;
                    }
                }
                
                if (!found) {
                    /* try again and reuse existing stream */
                    for(j=0;j<nb_istreams;j++) {
                        ist = ist_table[j];
                        if (ist->st->codec.codec_type == ost->st->codec.codec_type) {
                            ost->source_index = j;
                            found = 1;
                        }
                    }
                    if (!found) {
                        fprintf(stderr, "Could not find input stream matching output stream #%d.%d\n",
                                ost->file_index, ost->index);
                        exit(1);
                    }
                }
            }
            ist = ist_table[ost->source_index];
            ist->discard = 0;
        }
    }

    /* for each output stream, we compute the right encoding parameters */
    for(i=0;i<nb_ostreams;i++) {
        ost = ost_table[i];
        ist = ist_table[ost->source_index];

        codec = &ost->st->codec;
        icodec = &ist->st->codec;

        if (ost->st->stream_copy) {
            /* if stream_copy is selected, no need to decode or encode */
            codec->codec_id = icodec->codec_id;
            codec->codec_type = icodec->codec_type;
            if(!codec->codec_tag) codec->codec_tag = icodec->codec_tag;
            codec->bit_rate = icodec->bit_rate;
            codec->extradata= icodec->extradata;
            codec->extradata_size= icodec->extradata_size;
            switch(codec->codec_type) {
            case CODEC_TYPE_AUDIO:
                codec->sample_rate = icodec->sample_rate;
                codec->channels = icodec->channels;
                codec->frame_size = icodec->frame_size;
                codec->block_align= icodec->block_align;
                break;
            case CODEC_TYPE_VIDEO:
                codec->time_base = icodec->time_base;
                codec->width = icodec->width;
                codec->height = icodec->height;
                codec->has_b_frames = icodec->has_b_frames;
                break;
            default:
                av_abort();
            }
        } else {
            switch(codec->codec_type) {
            case CODEC_TYPE_AUDIO:
                if (fifo_init(&ost->fifo, 2 * MAX_AUDIO_PACKET_SIZE))
                    goto fail;
                
                if (codec->channels == icodec->channels &&
                    codec->sample_rate == icodec->sample_rate) {
                    ost->audio_resample = 0;
                } else {
                    if (codec->channels != icodec->channels &&
                        (icodec->codec_id == CODEC_ID_AC3 ||
                         icodec->codec_id == CODEC_ID_DTS)) {
                        /* Special case for 5:1 AC3 and DTS input */
                        /* and mono or stereo output      */
                        /* Request specific number of channels */
                        icodec->channels = codec->channels;
                        if (codec->sample_rate == icodec->sample_rate)
                            ost->audio_resample = 0;
                        else {
                            ost->audio_resample = 1;
                        }
                    } else {
                        ost->audio_resample = 1; 
                    }
                }
                if(audio_sync_method>1)
                    ost->audio_resample = 1;

                if(ost->audio_resample){
                    ost->resample = audio_resample_init(codec->channels, icodec->channels,
                                                    codec->sample_rate, icodec->sample_rate);
                    if(!ost->resample){
                        printf("Can't resample.  Aborting.\n");
                        av_abort();
                    }
                }
                ist->decoding_needed = 1;
                ost->encoding_needed = 1;
                break;
            case CODEC_TYPE_VIDEO:
                if (codec->width == icodec->width &&
                    codec->height == icodec->height &&
                    frame_topBand == 0 &&
                    frame_bottomBand == 0 &&
                    frame_leftBand == 0 &&
                    frame_rightBand == 0 && 
                    frame_padtop == 0 &&
                    frame_padbottom == 0 &&
                    frame_padleft == 0 &&
                    frame_padright == 0)
                {
                    ost->video_resample = 0;
                    ost->video_crop = 0;
                    ost->video_pad = 0;
                } else if ((codec->width == icodec->width -
                                (frame_leftBand + frame_rightBand)) &&
                        (codec->height == icodec->height -
                                (frame_topBand  + frame_bottomBand)))
                {
                    ost->video_resample = 0;
                    ost->video_crop = 1;
                    ost->topBand = frame_topBand;
                    ost->leftBand = frame_leftBand;
                } else if ((codec->width == icodec->width + 
                                (frame_padleft + frame_padright)) &&
                        (codec->height == icodec->height +
                                (frame_padtop + frame_padbottom))) {
                    ost->video_resample = 0;
                    ost->video_crop = 0;
                    ost->video_pad = 1;
                    ost->padtop = frame_padtop;
                    ost->padleft = frame_padleft;
                    ost->padbottom = frame_padbottom;
                    ost->padright = frame_padright;
                    avcodec_get_frame_defaults(&ost->pict_tmp);
                    if( avpicture_alloc( (AVPicture*)&ost->pict_tmp, PIX_FMT_YUV420P,
                                codec->width, codec->height ) )
                        goto fail;
                } else {
                    ost->video_resample = 1;
                    ost->video_crop = 0; // cropping is handled as part of resample
                    avcodec_get_frame_defaults(&ost->pict_tmp);
                    if( avpicture_alloc( (AVPicture*)&ost->pict_tmp, PIX_FMT_YUV420P,
                                         codec->width, codec->height ) )
                        goto fail;

                    ost->img_resample_ctx = img_resample_full_init( 
                                      ost->st->codec.width, ost->st->codec.height,
                                      ist->st->codec.width, ist->st->codec.height,
                                      frame_topBand, frame_bottomBand,
                            frame_leftBand, frame_rightBand, 
                            frame_padtop, frame_padbottom, 
                            frame_padleft, frame_padright);
                    
                    ost->padtop = frame_padtop;
                    ost->padleft = frame_padleft;
                    ost->padbottom = frame_padbottom;
                    ost->padright = frame_padright;
                   
                }
                ost->encoding_needed = 1;
                ist->decoding_needed = 1;
                break;
            default:
                av_abort();
            }
            /* two pass mode */
            if (ost->encoding_needed && 
                (codec->flags & (CODEC_FLAG_PASS1 | CODEC_FLAG_PASS2))) {
                char logfilename[1024];
                FILE *f;
                int size;
                char *logbuffer;
                
                snprintf(logfilename, sizeof(logfilename), "%s-%d.log", 
                         pass_logfilename ? 
                         pass_logfilename : DEFAULT_PASS_LOGFILENAME, i);
                if (codec->flags & CODEC_FLAG_PASS1) {
                    f = fopen(logfilename, "w");
                    if (!f) {
                        perror(logfilename);
                        exit(1);
                    }
                    ost->logfile = f;
                } else {
                    /* read the log file */
                    f = fopen(logfilename, "r");
                    if (!f) {
                        perror(logfilename);
                        exit(1);
                    }
                    fseek(f, 0, SEEK_END);
                    size = ftell(f);
                    fseek(f, 0, SEEK_SET);
                    logbuffer = av_malloc(size + 1);
                    if (!logbuffer) {
                        fprintf(stderr, "Could not allocate log buffer\n");
                        exit(1);
                    }
                    size = fread(logbuffer, 1, size, f);
                    fclose(f);
                    logbuffer[size] = '\0';
                    codec->stats_in = logbuffer;
                }
            }
        }
        if(codec->codec_type == CODEC_TYPE_VIDEO){
            int size= codec->width * codec->height;
            bit_buffer_size= FFMAX(bit_buffer_size, 4*size);
        }
    }

    if (!bit_buffer)
        bit_buffer = av_malloc(bit_buffer_size);
    if (!bit_buffer)
        goto fail;

    /* dump the file output parameters - cannot be done before in case
       of stream copy */
    for(i=0;i<nb_output_files;i++) {
        dump_format(output_files[i], i, output_files[i]->filename, 1);
    }

    /* dump the stream mapping */
    if (verbose >= 0) {
        fprintf(stderr, "Stream mapping:\n");
        for(i=0;i<nb_ostreams;i++) {
            ost = ost_table[i];
            fprintf(stderr, "  Stream #%d.%d -> #%d.%d\n",
                    ist_table[ost->source_index]->file_index,
                    ist_table[ost->source_index]->index,
                    ost->file_index, 
                    ost->index);
        }
    }

    /* open each encoder */
    for(i=0;i<nb_ostreams;i++) {
        ost = ost_table[i];
        if (ost->encoding_needed) {
            AVCodec *codec;
            codec = avcodec_find_encoder(ost->st->codec.codec_id);
            if (!codec) {
                fprintf(stderr, "Unsupported codec for output stream #%d.%d\n", 
                        ost->file_index, ost->index);
                exit(1);
            }
            if (avcodec_open(&ost->st->codec, codec) < 0) {
                fprintf(stderr, "Error while opening codec for output stream #%d.%d - maybe incorrect parameters such as bit_rate, rate, width or height\n", 
                        ost->file_index, ost->index);
                exit(1);
            }
            extra_size += ost->st->codec.extradata_size;
        }
    }

    /* open each decoder */
    for(i=0;i<nb_istreams;i++) {
        ist = ist_table[i];
        if (ist->decoding_needed) {
            AVCodec *codec;
            codec = avcodec_find_decoder(ist->st->codec.codec_id);
            if (!codec) {
                fprintf(stderr, "Unsupported codec (id=%d) for input stream #%d.%d\n", 
                        ist->st->codec.codec_id, ist->file_index, ist->index);
                exit(1);
            }
            if (avcodec_open(&ist->st->codec, codec) < 0) {
                fprintf(stderr, "Error while opening codec for input stream #%d.%d\n", 
                        ist->file_index, ist->index);
                exit(1);
            }
            //if (ist->st->codec.codec_type == CODEC_TYPE_VIDEO)
            //    ist->st->codec.flags |= CODEC_FLAG_REPEAT_FIELD;
        }
    }

    /* init pts */
    for(i=0;i<nb_istreams;i++) {
        ist = ist_table[i];
	is = input_files[ist->file_index];
        ist->pts = 0;
        ist->next_pts = av_rescale_q(ist->st->start_time, ist->st->time_base, AV_TIME_BASE_Q);
        if(ist->next_pts == AV_NOPTS_VALUE) 
            ist->next_pts=0;
        if(input_files_ts_offset[ist->file_index])
            ist->next_pts= AV_NOPTS_VALUE;
        ist->is_start = 1;
    }

    /* compute buffer size max (should use a complete heuristic) */
    for(i=0;i<nb_input_files;i++) {
        file_table[i].buffer_size_max = 2048;
    }

    /* set meta data information from input file if required */
    for (i=0;i<nb_meta_data_maps;i++) {
        AVFormatContext *out_file;
        AVFormatContext *in_file;

        int out_file_index = meta_data_maps[i].out_file;
        int in_file_index = meta_data_maps[i].in_file;
        if ( out