static int av_encode(AVFormatContext **output_files,

                     int nb_output_files,

                     AVFormatContext **input_files,

                     int nb_input_files,

                     AVStreamMap *stream_maps, int nb_stream_maps)

{

    int ret, i, j, k, n, nb_istreams = 0, nb_ostreams = 0;

    AVFormatContext *is, *os;

    AVCodecContext *codec, *icodec;

    AVOutputStream *ost, **ost_table = NULL;

    AVInputStream *ist, **ist_table = NULL;

    AVInputFile *file_table;

    AVFormatContext *stream_no_data;

    int key;



    file_table= (AVInputFile*) av_mallocz(nb_input_files * sizeof(AVInputFile));

    if (!file_table)

        goto fail;



    /* input stream init */

    j = 0;

    for(i=0;i<nb_input_files;i++) {

        is = input_files[i];

        file_table[i].ist_index = j;

        file_table[i].nb_streams = is->nb_streams;

        j += is->nb_streams;

    }

    nb_istreams = j;



    ist_table = av_mallocz(nb_istreams * sizeof(AVInputStream *));

    if (!ist_table)

        goto fail;

    

    for(i=0;i<nb_istreams;i++) {

        ist = av_mallocz(sizeof(AVInputStream));

        if (!ist)

            goto fail;

        ist_table[i] = ist;

    }

    j = 0;

    for(i=0;i<nb_input_files;i++) {

        is = input_files[i];

        for(k=0;k<is->nb_streams;k++) {

            ist = ist_table[j++];

            ist->st = is->streams[k];

            ist->file_index = i;

            ist->index = k;

            ist->discard = 1; /* the stream is discarded by default

                                 (changed later) */



            if (ist->st->codec.rate_emu) {

                ist->start = av_gettime();

                ist->frame = 0;

            }

        }

    }



    /* output stream init */

    nb_ostreams = 0;

    for(i=0;i<nb_output_files;i++) {

        os = output_files[i];

        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;

                    }

                }

                

                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;

            codec->codec_tag = icodec->codec_tag;

            codec->bit_rate = icodec->bit_rate;

            switch(codec->codec_type) {

            case CODEC_TYPE_AUDIO:

                codec->sample_rate = icodec->sample_rate;

                codec->channels = icodec->channels;

                break;

            case CODEC_TYPE_VIDEO:

                codec->frame_rate = icodec->frame_rate;

                codec->frame_rate_base = icodec->frame_rate_base;

                codec->width = icodec->width;

                codec->height = icodec->height;

                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) {

                        /* Special case for 5:1 AC3 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;

                            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();

			      }

                        }

                        /* Request specific number of channels */

                        icodec->channels = codec->channels;

                    } else {

                        ost->audio_resample = 1; 

                        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)

                {

                    ost->video_resample = 0;

                    ost->video_crop = 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 {

                    uint8_t *buf;

                    ost->video_resample = 1;

                    ost->video_crop = 0; // cropping is handled as part of resample

                    buf = av_malloc((codec->width * codec->height * 3) / 2);

                    if (!buf)

                        goto fail;

                    ost->pict_tmp.data[0] = buf;

                    ost->pict_tmp.data[1] = ost->pict_tmp.data[0] + (codec->width * codec->height);

                    ost->pict_tmp.data[2] = ost->pict_tmp.data[1] + (codec->width * codec->height) / 4;

                    ost->pict_tmp.linesize[0] = codec->width;

                    ost->pict_tmp.linesize[1] = codec->width / 2;

                    ost->pict_tmp.linesize[2] = codec->width / 2;



                    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);

                }

                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);

                    }

                    fread(logbuffer, 1, size, f);

                    fclose(f);

                    logbuffer[size] = '\0';

                    codec->stats_in = logbuffer;

                }

            }

        }

    }



    /* 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 */

    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 stream #%d.%d - maybe incorrect parameters such as bit_rate, rate, width or height\n", 

                        ost->file_index, ost->index);

                exit(1);

            }

        }

    }



    /* 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;

            ist->frame_decoded = 1;

        }

    }



    /* init pts */

    for(i=0;i<nb_istreams;i++) {

        ist = ist_table[i];

	is = input_files[ist->file_index];

        ist->pts = 0;

        if (ist->decoding_needed) {

            switch (ist->st->codec.codec_type) {

            case CODEC_TYPE_AUDIO:

                av_frac_init(&ist->next_pts, 

                             0, 0, is->pts_num * ist->st->codec.sample_rate);

                break;

            case CODEC_TYPE_VIDEO:

                av_frac_init(&ist->next_pts, 

                             0, 0, is->pts_num * ist->st->codec.frame_rate);

                break;

            default:

                break;

            }

        }

    }

    

    /* compute buffer size max (should use a complete heuristic) */

    for(i=0;i<nb_input_files;i++) {

        file_table[i].buffer_size_max = 2048;

    }



    /* open files and write file headers */

    for(i=0;i<nb_output_files;i++) {

        os = output_files[i];

        if (av_write_header(os) < 0) {

            fprintf(stderr, "Could not write header for output file #%d (incorrect codec paramters ?)\n", i);

            ret = -EINVAL;

            goto fail;

        }

    }



#ifndef CONFIG_WIN32

    if ( !using_stdin )

        fprintf(stderr, "Press [q] to stop encoding\n");

#endif

    term_init();



    stream_no_data = 0;

    key = -1;



    for(; received_sigterm == 0;) {

        int file_index, ist_index;

        AVPacket pkt;

        uint8_t *ptr;

        int len;

        uint8_t *data_buf;

        int data_size, got_picture;

        AVPicture picture;

        short samples[AVCODEC_MAX_AUDIO_FRAME_SIZE / 2];

        void *buffer_to_free;

        double pts_min;

        

    redo:

        /* if 'q' pressed, exits */

        if (!using_stdin) {

            /* read_key() returns 0 on EOF */

            key = read_key();

            if (key == 'q')

                break;

        }



        /* select the stream that we must read now by looking at the

           smallest output pts */

        file_index = -1;

        pts_min = 1e10;

        for(i=0;i<nb_ostreams;i++) {

            double pts;

            ost = ost_table[i];

            os = output_files[ost->file_index];

            ist = ist_table[ost->source_index];

            pts = (double)ost->st->pts.val * os->pts_num / os->pts_den;

            if (!file_table[ist->file_index].eof_reached && 

                pts < pts_min) {

                pts_min = pts;

                file_index = ist->file_index;

            }

        }

        /* if none, if is finished */

        if (file_index < 0) {

            break;

        }



        /* finish if recording time exhausted */

        if (recording_time > 0 && pts_min >= (recording_time / 1000000.0))

            break;



        /* read a packet from it and output it in the fifo */

        is = input_files[file_index];

        if (av_read_packet(is, &pkt) < 0) {

            file_table[file_index].eof_reached = 1;

            continue;

        }

        if (!pkt.size) {

            stream_no_data = is;

        } else {

            stream_no_data = 0;

        }

        if (do_hex_dump) {

            printf("stream #%d, size=%d:\n", pkt.stream_index, pkt.size);

            av_hex_dump(pkt.data, pkt.size);

        }

        /* the following test is needed in case new streams appear

           dynamically in stream : we ignore them */

        if (pkt.stream_index >= file_table[file_index].nb_streams)

            goto discard_packet;

        ist_index = file_table[file_index].ist_index + pkt.stream_index;

        ist = ist_table[ist_index];

        if (ist->discard)

            goto discard_packet;



        // printf("read #%d.%d size=%d\n", ist->file_index, ist->index, pkt.size);



        len = pkt.size;

        ptr = pkt.data;

        while (len > 0) {

            /* decode the packet if needed */

            data_buf = NULL; /* fail safe */

            data_size = 0;

            if (ist->decoding_needed) {

                /* NOTE1: we only take into account the PTS if a new

                   frame has begun (MPEG semantics) */

                /* NOTE2: even if the fraction is not initialized,

                   av_frac_set can be used to set the integer part */

                if (ist->frame_decoded) { 

                    /* If pts is unavailable -- we have to use synthetic one */

                    if( pkt.pts != AV_NOPTS_VALUE )

                    {

                        ist->pts = ist->next_pts.val = pkt.pts;

                    }

                    else

                    {

                        ist->pts = ist->next_pts.val;

                    }

                    ist->frame_decoded = 0;

                }



                switch(ist->st->codec.codec_type) {

                case CODEC_TYPE_AUDIO:

                    /* XXX: could avoid copy if PCM 16 bits with same

                       endianness as CPU */

                    ret = avcodec_decode_audio(&ist->st->codec, samples, &data_size,

                                               ptr, len);

                    if (ret < 0)

                        goto fail_decode;

                    /* Some bug in mpeg audio decoder gives */

                    /* data_size < 0, it seems they are overflows */

                    if (data_size <= 0) {

                        /* no audio frame */

                        ptr += ret;

                        len -= ret;

                        continue;

                    }

                    data_buf = (uint8_t *)samples;

		    av_frac_add(&ist->next_pts, 

			        is->pts_den * data_size / (2 * ist->st->codec.channels));

                    break;

                case CODEC_TYPE_VIDEO:

                    {

                        AVFrame big_picture;



                        data_size = (ist->st->codec.width * ist->st->codec.height * 3) / 2;

                        ret = avcodec_decode_video(&ist->st->codec, 

                                                   &big_picture, &got_picture, ptr, len);

                        picture= *(AVPicture*)&big_picture;

                        ist->st->quality= big_picture.quality;

                        if (ret < 0) {

                        fail_decode:

                            fprintf(stderr, "Error while decoding stream #%d.%d\n",

                                    ist->file_index, ist->index);

                            av_free_packet(&pkt);

                            goto redo;

                        }

                        if (!got_picture) {

                            /* no picture yet */

                            ptr += ret;

                            len -= ret;

                            continue;

                        }

                        av_frac_add(&ist->next_pts, 

			            is->pts_den * ist->st->codec.frame_rate_base);          

                    }

                    break;

                default:

                    goto fail_decode;

                }

            } else {

                data_buf = ptr;

                data_size = len;

                ret = len;

            }

            ptr += ret;

            len -= ret;



            buffer_to_free = 0;

            if (ist->st->codec.codec_type == CODEC_TYPE_VIDEO) {

                pre_process_video_frame(ist, &picture, &buffer_to_free);

            }



            ist->frame_decoded = 1;



            /* frame rate emulation */

            if (ist->st->codec.rate_emu) {

                int64_t pts = av_rescale((int64_t) ist->frame * ist->st->codec.frame_rate_base, 1000000, ist->st->codec.frame_rate);

                int64_t now = av_gettime() - ist->start;

                if (pts > now)

                    usleep(pts - now);



                ist->frame++;

            }



#if 0

            /* mpeg PTS deordering : if it is a P or I frame, the PTS

               is the one of the next displayed one */

            /* XXX: add mpeg4 too ? */

            if (ist->st->codec.codec_id == CODEC_ID_MPEG1VIDEO) {

                if (ist->st->codec.pict_type != B_TYPE) {

                    int64_t tmp;

                    tmp = ist->last_ip_pts;

                    ist->last_ip_pts  = ist->frac_pts.val;

                    ist->frac_pts.val = tmp;

                }

            }

#endif

            /* transcode raw format, encode packets and output them */



            for(i=0;i<nb_ostreams;i++) {

                int frame_size;



                ost = ost_table[i];

                if (ost->source_index == ist_index) {

                    os = output_files[ost->file_index];



#if 0

                    printf("%d: got pts=%f %f\n", i, pkt.pts / 90000.0, 

                           (ist->pts - ost->st->pts.val) / 90000.0);

#endif

                    /* set the input output pts pairs */

                    ost->sync_ipts = (double)ist->pts * is->pts_num / 

                        is->pts_den;

                    /* XXX: take into account the various fifos,

                       in particular for audio */

                    ost->sync_opts = ost->st->pts.val;

                    //printf("ipts=%lld sync_ipts=%f sync_opts=%lld pts.val=%lld pkt.pts=%lld\n", ist->pts, ost->sync_ipts, ost->sync_opts, ost->st->pts.val, pkt.pts); 



                    if (ost->encoding_needed) {

                        switch(ost->st->codec.codec_type) {

                        case CODEC_TYPE_AUDIO:

                            do_audio_out(os, ost, ist, data_buf, data_size);

                            break;

                        case CODEC_TYPE_VIDEO:

                            /* find an audio stream for synchro */

                            {

                                int i;

                                AVOutputStream *audio_sync, *ost1;

                                audio_sync = NULL;

                                for(i=0;i<nb_ostreams;i++) {

                                    ost1 = ost_table[i];

                                    if (ost1->file_index == ost->file_index &&

                                        ost1->st->codec.codec_type == CODEC_TYPE_AUDIO) {

                                        audio_sync = ost1;

                                        break;

                                    }

                                }



                                do_video_out(os, ost, ist, &picture, &frame_size, audio_sync);

                                if (do_vstats && frame_size)

                                    do_video_stats(os, ost, frame_size);

                            }

                            break;

                        default:

                            av_abort();

                        }

                    } else {

                        AVFrame avframe;

                                                

                        /* no reencoding needed : output the packet directly */

                        /* force the input stream PTS */

                        

                        memset(&avframe, 0, sizeof(AVFrame));

                        ost->st->codec.coded_frame= &avframe;

			avframe.key_frame = pkt.flags & PKT_FLAG_KEY; 

                        

                        av_write_frame(os, ost->index, data_buf, data_size);

			ost->st->codec.frame_number++;

			ost->frame_number++;

                    }

                }

            }

            av_free(buffer_to_free);

        }

    discard_packet:

        av_free_packet(&pkt);

        

        /* dump report by using the output first video and audio streams */

        print_report(output_files, ost_table, nb_ostreams, 0);

    }

    term_exit();



    /* dump report by using the first video and audio streams */

    print_report(output_files, ost_table, nb_ostreams, 1);



    /* close each encoder */

    for(i=0;i<nb_ostreams;i++) {

        ost = ost_table[i];

        if (ost->encoding_needed) {

            av_freep(&ost->st->codec.stats_in);

            avcodec_close(&ost->st->codec);

        }

    }

    

    /* close each decoder */

    for(i=0;i<nb_istreams;i++) {

        ist = ist_table[i];

        if (ist->decoding_needed) {

            avcodec_close(&ist->st->codec);

        }

    }

    



    /* write the trailer if needed and close file */

    for(i=0;i<nb_output_files;i++) {

        os = output_files[i];

        av_write_trailer(os);

    }

    /* finished ! */

    

    ret = 0;

 fail1:

    av_free(file_table);



    if (ist_table) {

        for(i=0;i<nb_istreams;i++) {

            ist = ist_table[i];

            av_free(ist);

        }

        av_free(ist_table);

    }

    if (ost_table) {

        for(i=0;i<nb_ostreams;i++) {

            ost = ost_table[i];

            if (ost) {

                if (ost->logfile) {

                    fclose(ost->logfile);

                    ost->logfile = NULL;

                }

                fifo_free(&ost->fifo); /* works even if fifo is not

                                          initialized but set to zero */

                av_free(ost->pict_tmp.data[0]);

                if (ost->video_resample)

                    img_resample_close(ost->img_resample_ctx);

                if (ost->audio_resample)

                    audio_resample_close(ost->resample);

                av_free(ost);

            }

        }

        av_free(ost_table);

    }

    return ret;

 fail:

    ret = -ENOMEM;

    goto fail1;

}
