ffmpeg_opt.c

       first frames to get it. (used in mpeg case for example) */
    ret = avformat_find_stream_info(ic, opts);
    if (ret < 0) {
        av_log(NULL, AV_LOG_FATAL, "%s: could not find codec parameters\n", filename);
        if (ic->nb_streams == 0) {
            avformat_close_input(&ic);
            exit_program(1);
        }
    }

    if (o->start_time_eof != AV_NOPTS_VALUE) {
        if (ic->duration>0) {
            o->start_time = o->start_time_eof + ic->duration;
        } else
            av_log(NULL, AV_LOG_WARNING, "Cannot use -sseof, duration of %s not known\n", filename);
    }
    timestamp = (o->start_time == AV_NOPTS_VALUE) ? 0 : o->start_time;
    /* add the stream start time */
    if (!o->seek_timestamp && ic->start_time != AV_NOPTS_VALUE)
        timestamp += ic->start_time;

    /* if seeking requested, we execute it */
    if (o->start_time != AV_NOPTS_VALUE) {
        int64_t seek_timestamp = timestamp;

        if (!(ic->iformat->flags & AVFMT_SEEK_TO_PTS)) {
            int dts_heuristic = 0;
            for (i=0; i<ic->nb_streams; i++) {
                AVCodecContext *avctx = ic->streams[i]->codec;
                if (avctx->has_b_frames)
                    dts_heuristic = 1;
            }
            if (dts_heuristic) {
                seek_timestamp -= 3*AV_TIME_BASE / 23;
            }
        }
        ret = avformat_seek_file(ic, -1, INT64_MIN, seek_timestamp, seek_timestamp, 0);
        if (ret < 0) {
            av_log(NULL, AV_LOG_WARNING, "%s: could not seek to position %0.3f\n",
                   filename, (double)timestamp / AV_TIME_BASE);
        }
    }

    /* update the current parameters so that they match the one of the input stream */
    add_input_streams(o, ic);

    /* dump the file content */
    av_dump_format(ic, nb_input_files, filename, 0);

    GROW_ARRAY(input_files, nb_input_files);
    f = av_mallocz(sizeof(*f));
    if (!f)
        exit_program(1);
    input_files[nb_input_files - 1] = f;

    f->ctx        = ic;
    f->ist_index  = nb_input_streams - ic->nb_streams;
    f->start_time = o->start_time;
    f->recording_time = o->recording_time;
    f->input_ts_offset = o->input_ts_offset;
    f->ts_offset  = o->input_ts_offset - (copy_ts ? (start_at_zero && ic->start_time != AV_NOPTS_VALUE ? ic->start_time : 0) : timestamp);
    f->nb_streams = ic->nb_streams;
    f->rate_emu   = o->rate_emu;
    f->accurate_seek = o->accurate_seek;
    f->loop = o->loop;
    f->duration = 0;
    f->time_base = (AVRational){ 1, 1 };
#if HAVE_PTHREADS
    f->thread_queue_size = o->thread_queue_size > 0 ? o->thread_queue_size : 8;
#endif

    /* check if all codec options have been used */
    unused_opts = strip_specifiers(o->g->codec_opts);
    for (i = f->ist_index; i < nb_input_streams; i++) {
        e = NULL;
        while ((e = av_dict_get(input_streams[i]->decoder_opts, "", e,
                                AV_DICT_IGNORE_SUFFIX)))
            av_dict_set(&unused_opts, e->key, NULL, 0);
    }

    e = NULL;
    while ((e = av_dict_get(unused_opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
        const AVClass *class = avcodec_get_class();
        const AVOption *option = av_opt_find(&class, e->key, NULL, 0,
                                             AV_OPT_SEARCH_CHILDREN | AV_OPT_SEARCH_FAKE_OBJ);
        const AVClass *fclass = avformat_get_class();
        const AVOption *foption = av_opt_find(&fclass, e->key, NULL, 0,
                                             AV_OPT_SEARCH_CHILDREN | AV_OPT_SEARCH_FAKE_OBJ);
        if (!option || foption)
            continue;


        if (!(option->flags & AV_OPT_FLAG_DECODING_PARAM)) {
            av_log(NULL, AV_LOG_ERROR, "Codec AVOption %s (%s) specified for "
                   "input file #%d (%s) is not a decoding option.\n", e->key,
                   option->help ? option->help : "", nb_input_files - 1,
                   filename);
            exit_program(1);
        }

        av_log(NULL, AV_LOG_WARNING, "Codec AVOption %s (%s) specified for "
               "input file #%d (%s) has not been used for any stream. The most "
               "likely reason is either wrong type (e.g. a video option with "
               "no video streams) or that it is a private option of some decoder "
               "which was not actually used for any stream.\n", e->key,
               option->help ? option->help : "", nb_input_files - 1, filename);
    }
    av_dict_free(&unused_opts);

    for (i = 0; i < o->nb_dump_attachment; i++) {
        int j;

        for (j = 0; j < ic->nb_streams; j++) {
            AVStream *st = ic->streams[j];

            if (check_stream_specifier(ic, st, o->dump_attachment[i].specifier) == 1)
                dump_attachment(st, o->dump_attachment[i].u.str);
        }
    }

    for (i = 0; i < orig_nb_streams; i++)
        av_dict_free(&opts[i]);
    av_freep(&opts);

    input_stream_potentially_available = 1;

    return 0;
}

static uint8_t *get_line(AVIOContext *s)
{
    AVIOContext *line;
    uint8_t *buf;
    char c;

    if (avio_open_dyn_buf(&line) < 0) {
        av_log(NULL, AV_LOG_FATAL, "Could not alloc buffer for reading preset.\n");
        exit_program(1);
    }

    while ((c = avio_r8(s)) && c != '\n')
        avio_w8(line, c);
    avio_w8(line, 0);
    avio_close_dyn_buf(line, &buf);

    return buf;
}

static int get_preset_file_2(const char *preset_name, const char *codec_name, AVIOContext **s)
{
    int i, ret = -1;
    char filename[1000];
    const char *base[3] = { getenv("AVCONV_DATADIR"),
                            getenv("HOME"),
                            AVCONV_DATADIR,
                            };

    for (i = 0; i < FF_ARRAY_ELEMS(base) && ret < 0; i++) {
        if (!base[i])
            continue;
        if (codec_name) {
            snprintf(filename, sizeof(filename), "%s%s/%s-%s.avpreset", base[i],
                     i != 1 ? "" : "/.avconv", codec_name, preset_name);
            ret = avio_open2(s, filename, AVIO_FLAG_READ, &int_cb, NULL);
        }
        if (ret < 0) {
            snprintf(filename, sizeof(filename), "%s%s/%s.avpreset", base[i],
                     i != 1 ? "" : "/.avconv", preset_name);
            ret = avio_open2(s, filename, AVIO_FLAG_READ, &int_cb, NULL);
        }
    }
    return ret;
}

static void choose_encoder(OptionsContext *o, AVFormatContext *s, OutputStream *ost)
{
    char *codec_name = NULL;

    MATCH_PER_STREAM_OPT(codec_names, str, codec_name, s, ost->st);
    if (!codec_name) {
        ost->st->codec->codec_id = av_guess_codec(s->oformat, NULL, s->filename,
                                                  NULL, ost->st->codec->codec_type);
        ost->enc = avcodec_find_encoder(ost->st->codec->codec_id);
    } else if (!strcmp(codec_name, "copy"))
        ost->stream_copy = 1;
    else {
        ost->enc = find_codec_or_die(codec_name, ost->st->codec->codec_type, 1);
        ost->st->codec->codec_id = ost->enc->id;
    }
}

static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, enum AVMediaType type, int source_index)
{
    OutputStream *ost;
    AVStream *st = avformat_new_stream(oc, NULL);
    int idx      = oc->nb_streams - 1, ret = 0;
    char *bsf = NULL, *next, *codec_tag = NULL;
    AVBitStreamFilterContext *bsfc, *bsfc_prev = NULL;
    double qscale = -1;
    int i;

    if (!st) {
        av_log(NULL, AV_LOG_FATAL, "Could not alloc stream.\n");
        exit_program(1);
    }

    if (oc->nb_streams - 1 < o->nb_streamid_map)
        st->id = o->streamid_map[oc->nb_streams - 1];

    GROW_ARRAY(output_streams, nb_output_streams);
    if (!(ost = av_mallocz(sizeof(*ost))))
        exit_program(1);
    output_streams[nb_output_streams - 1] = ost;

    ost->file_index = nb_output_files - 1;
    ost->index      = idx;
    ost->st         = st;
    st->codec->codec_type = type;
    choose_encoder(o, oc, ost);

    ost->enc_ctx = avcodec_alloc_context3(ost->enc);
    if (!ost->enc_ctx) {
        av_log(NULL, AV_LOG_ERROR, "Error allocating the encoding context.\n");
        exit_program(1);
    }
    ost->enc_ctx->codec_type = type;

    if (ost->enc) {
        AVIOContext *s = NULL;
        char *buf = NULL, *arg = NULL, *preset = NULL;

        ost->encoder_opts  = filter_codec_opts(o->g->codec_opts, ost->enc->id, oc, st, ost->enc);

        MATCH_PER_STREAM_OPT(presets, str, preset, oc, st);
        if (preset && (!(ret = get_preset_file_2(preset, ost->enc->name, &s)))) {
            do  {
                buf = get_line(s);
                if (!buf[0] || buf[0] == '#') {
                    av_free(buf);
                    continue;
                }
                if (!(arg = strchr(buf, '='))) {
                    av_log(NULL, AV_LOG_FATAL, "Invalid line found in the preset file.\n");
                    exit_program(1);
                }
                *arg++ = 0;
                av_dict_set(&ost->encoder_opts, buf, arg, AV_DICT_DONT_OVERWRITE);
                av_free(buf);
            } while (!s->eof_reached);
            avio_closep(&s);
        }
        if (ret) {
            av_log(NULL, AV_LOG_FATAL,
                   "Preset %s specified for stream %d:%d, but could not be opened.\n",
                   preset, ost->file_index, ost->index);
            exit_program(1);
        }
    } else {
        ost->encoder_opts = filter_codec_opts(o->g->codec_opts, AV_CODEC_ID_NONE, oc, st, NULL);
    }

    ost->max_frames = INT64_MAX;
    MATCH_PER_STREAM_OPT(max_frames, i64, ost->max_frames, oc, st);
    for (i = 0; i<o->nb_max_frames; i++) {
        char *p = o->max_frames[i].specifier;
        if (!*p && type != AVMEDIA_TYPE_VIDEO) {
            av_log(NULL, AV_LOG_WARNING, "Applying unspecific -frames to non video streams, maybe you meant -vframes ?\n");
            break;
        }
    }

    ost->copy_prior_start = -1;
    MATCH_PER_STREAM_OPT(copy_prior_start, i, ost->copy_prior_start, oc ,st);

    MATCH_PER_STREAM_OPT(bitstream_filters, str, bsf, oc, st);
    while (bsf) {
        char *arg = NULL;
        if (next = strchr(bsf, ','))
            *next++ = 0;
        if (arg = strchr(bsf, '='))
            *arg++ = 0;
        if (!(bsfc = av_bitstream_filter_init(bsf))) {
            av_log(NULL, AV_LOG_FATAL, "Unknown bitstream filter %s\n", bsf);
            exit_program(1);
        }
        if (bsfc_prev)
            bsfc_prev->next = bsfc;
        else
            ost->bitstream_filters = bsfc;
        if (arg)
            if (!(bsfc->args = av_strdup(arg))) {
                av_log(NULL, AV_LOG_FATAL, "Bitstream filter memory allocation failed\n");
                exit_program(1);
            }

        bsfc_prev = bsfc;
        bsf       = next;
    }

    MATCH_PER_STREAM_OPT(codec_tags, str, codec_tag, oc, st);
    if (codec_tag) {
        uint32_t tag = strtol(codec_tag, &next, 0);
        if (*next)
            tag = AV_RL32(codec_tag);
        ost->st->codec->codec_tag =
        ost->enc_ctx->codec_tag = tag;
    }

    MATCH_PER_STREAM_OPT(qscale, dbl, qscale, oc, st);
    if (qscale >= 0) {
        ost->enc_ctx->flags |= AV_CODEC_FLAG_QSCALE;
        ost->enc_ctx->global_quality = FF_QP2LAMBDA * qscale;
    }

    MATCH_PER_STREAM_OPT(disposition, str, ost->disposition, oc, st);
    ost->disposition = av_strdup(ost->disposition);

    if (oc->oformat->flags & AVFMT_GLOBALHEADER)
        ost->enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;

    av_dict_copy(&ost->sws_dict, o->g->sws_dict, 0);

    av_dict_copy(&ost->swr_opts, o->g->swr_opts, 0);
    if (ost->enc && av_get_exact_bits_per_sample(ost->enc->id) == 24)
        av_dict_set(&ost->swr_opts, "output_sample_bits", "24", 0);

    av_dict_copy(&ost->resample_opts, o->g->resample_opts, 0);

    ost->source_index = source_index;
    if (source_index >= 0) {
        ost->sync_ist = input_streams[source_index];
        input_streams[source_index]->discard = 0;
        input_streams[source_index]->st->discard = input_streams[source_index]->user_set_discard;
    }
    ost->last_mux_dts = AV_NOPTS_VALUE;

    return ost;
}

static void parse_matrix_coeffs(uint16_t *dest, const char *str)
{
    int i;
    const char *p = str;
    for (i = 0;; i++) {
        dest[i] = atoi(p);
        if (i == 63)
            break;
        p = strchr(p, ',');
        if (!p) {
            av_log(NULL, AV_LOG_FATAL, "Syntax error in matrix \"%s\" at coeff %d\n", str, i);
            exit_program(1);
        }
        p++;
    }
}

/* read file contents into a string */
static uint8_t *read_file(const char *filename)
{
    AVIOContext *pb      = NULL;
    AVIOContext *dyn_buf = NULL;
    int ret = avio_open(&pb, filename, AVIO_FLAG_READ);
    uint8_t buf[1024], *str;

    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error opening file %s.\n", filename);
        return NULL;
    }

    ret = avio_open_dyn_buf(&dyn_buf);
    if (ret < 0) {
        avio_closep(&pb);
        return NULL;
    }
    while ((ret = avio_read(pb, buf, sizeof(buf))) > 0)
        avio_write(dyn_buf, buf, ret);
    avio_w8(dyn_buf, 0);
    avio_closep(&pb);

    ret = avio_close_dyn_buf(dyn_buf, &str);
    if (ret < 0)
        return NULL;
    return str;
}

static char *get_ost_filters(OptionsContext *o, AVFormatContext *oc,
                             OutputStream *ost)
{
    AVStream *st = ost->st;

    if (ost->filters_script && ost->filters) {
        av_log(NULL, AV_LOG_ERROR, "Both -filter and -filter_script set for "
               "output stream #%d:%d.\n", nb_output_files, st->index);
        exit_program(1);
    }

    if (ost->filters_script)
        return read_file(ost->filters_script);
    else if (ost->filters)
        return av_strdup(ost->filters);

    return av_strdup(st->codec->codec_type == AVMEDIA_TYPE_VIDEO ?
                     "null" : "anull");
}

static void check_streamcopy_filters(OptionsContext *o, AVFormatContext *oc,
                                     const OutputStream *ost, enum AVMediaType type)
{
    if (ost->filters_script || ost->filters) {
        av_log(NULL, AV_LOG_ERROR,
               "%s '%s' was defined for %s output stream %d:%d but codec copy was selected.\n"
               "Filtering and streamcopy cannot be used together.\n",
               ost->filters ? "Filtergraph" : "Filtergraph script",
               ost->filters ? ost->filters : ost->filters_script,
               av_get_media_type_string(type), ost->file_index, ost->index);
        exit_program(1);
    }
}

static OutputStream *new_video_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    AVStream *st;
    OutputStream *ost;
    AVCodecContext *video_enc;
    char *frame_rate = NULL, *frame_aspect_ratio = NULL;

    ost = new_output_stream(o, oc, AVMEDIA_TYPE_VIDEO, source_index);
    st  = ost->st;
    video_enc = ost->enc_ctx;

    MATCH_PER_STREAM_OPT(frame_rates, str, frame_rate, oc, st);
    if (frame_rate && av_parse_video_rate(&ost->frame_rate, frame_rate) < 0) {
        av_log(NULL, AV_LOG_FATAL, "Invalid framerate value: %s\n", frame_rate);
        exit_program(1);
    }
    if (frame_rate && video_sync_method == VSYNC_PASSTHROUGH)
        av_log(NULL, AV_LOG_ERROR, "Using -vsync 0 and -r can produce invalid output files\n");

    MATCH_PER_STREAM_OPT(frame_aspect_ratios, str, frame_aspect_ratio, oc, st);
    if (frame_aspect_ratio) {
        AVRational q;
        if (av_parse_ratio(&q, frame_aspect_ratio, 255, 0, NULL) < 0 ||
            q.num <= 0 || q.den <= 0) {
            av_log(NULL, AV_LOG_FATAL, "Invalid aspect ratio: %s\n", frame_aspect_ratio);
            exit_program(1);
        }
        ost->frame_aspect_ratio = q;
    }

    MATCH_PER_STREAM_OPT(filter_scripts, str, ost->filters_script, oc, st);
    MATCH_PER_STREAM_OPT(filters,        str, ost->filters,        oc, st);

    if (!ost->stream_copy) {
        const char *p = NULL;
        char *frame_size = NULL;
        char *frame_pix_fmt = NULL;
        char *intra_matrix = NULL, *inter_matrix = NULL;
        char *chroma_intra_matrix = NULL;
        int do_pass = 0;
        int i;

        MATCH_PER_STREAM_OPT(frame_sizes, str, frame_size, oc, st);
        if (frame_size && av_parse_video_size(&video_enc->width, &video_enc->height, frame_size) < 0) {
            av_log(NULL, AV_LOG_FATAL, "Invalid frame size: %s.\n", frame_size);
            exit_program(1);
        }

        video_enc->bits_per_raw_sample = frame_bits_per_raw_sample;
        MATCH_PER_STREAM_OPT(frame_pix_fmts, str, frame_pix_fmt, oc, st);
        if (frame_pix_fmt && *frame_pix_fmt == '+') {
            ost->keep_pix_fmt = 1;
            if (!*++frame_pix_fmt)
                frame_pix_fmt = NULL;
        }
        if (frame_pix_fmt && (video_enc->pix_fmt = av_get_pix_fmt(frame_pix_fmt)) == AV_PIX_FMT_NONE) {
            av_log(NULL, AV_LOG_FATAL, "Unknown pixel format requested: %s.\n", frame_pix_fmt);
            exit_program(1);
        }
        st->sample_aspect_ratio = video_enc->sample_aspect_ratio;

        if (intra_only)
            video_enc->gop_size = 0;
        MATCH_PER_STREAM_OPT(intra_matrices, str, intra_matrix, oc, st);
        if (intra_matrix) {
            if (!(video_enc->intra_matrix = av_mallocz(sizeof(*video_enc->intra_matrix) * 64))) {
                av_log(NULL, AV_LOG_FATAL, "Could not allocate memory for intra matrix.\n");
                exit_program(1);
            }
            parse_matrix_coeffs(video_enc->intra_matrix, intra_matrix);
        }
        MATCH_PER_STREAM_OPT(chroma_intra_matrices, str, chroma_intra_matrix, oc, st);
        if (chroma_intra_matrix) {
            uint16_t *p = av_mallocz(sizeof(*video_enc->chroma_intra_matrix) * 64);
            if (!p) {
                av_log(NULL, AV_LOG_FATAL, "Could not allocate memory for intra matrix.\n");
                exit_program(1);
            }
            av_codec_set_chroma_intra_matrix(video_enc, p);
            parse_matrix_coeffs(p, chroma_intra_matrix);
        }
        MATCH_PER_STREAM_OPT(inter_matrices, str, inter_matrix, oc, st);
        if (inter_matrix) {
            if (!(video_enc->inter_matrix = av_mallocz(sizeof(*video_enc->inter_matrix) * 64))) {
                av_log(NULL, AV_LOG_FATAL, "Could not allocate memory for inter matrix.\n");
                exit_program(1);
            }
            parse_matrix_coeffs(video_enc->inter_matrix, inter_matrix);
        }

        MATCH_PER_STREAM_OPT(rc_overrides, str, p, oc, st);
        for (i = 0; p; i++) {
            int start, end, q;
            int e = sscanf(p, "%d,%d,%d", &start, &end, &q);
            if (e != 3) {
                av_log(NULL, AV_LOG_FATAL, "error parsing rc_override\n");
                exit_program(1);
            }
            video_enc->rc_override =
                av_realloc_array(video_enc->rc_override,
                                 i + 1, sizeof(RcOverride));
            if (!video_enc->rc_override) {
                av_log(NULL, AV_LOG_FATAL, "Could not (re)allocate memory for rc_override.\n");
                exit_program(1);
            }
            video_enc->rc_override[i].start_frame = start;
            video_enc->rc_override[i].end_frame   = end;
            if (q > 0) {
                video_enc->rc_override[i].qscale         = q;
                video_enc->rc_override[i].quality_factor = 1.0;
            }
            else {
                video_enc->rc_override[i].qscale         = 0;
                video_enc->rc_override[i].quality_factor = -q/100.0;
            }
            p = strchr(p, '/');
            if (p) p++;
        }
        video_enc->rc_override_count = i;

        if (do_psnr)
            video_enc->flags|= AV_CODEC_FLAG_PSNR;

        /* two pass mode */
        MATCH_PER_STREAM_OPT(pass, i, do_pass, oc, st);
        if (do_pass) {
            if (do_pass & 1) {
                video_enc->flags |= AV_CODEC_FLAG_PASS1;
                av_dict_set(&ost->encoder_opts, "flags", "+pass1", AV_DICT_APPEND);
            }
            if (do_pass & 2) {
                video_enc->flags |= AV_CODEC_FLAG_PASS2;
                av_dict_set(&ost->encoder_opts, "flags", "+pass2", AV_DICT_APPEND);
            }
        }

        MATCH_PER_STREAM_OPT(passlogfiles, str, ost->logfile_prefix, oc, st);
        if (ost->logfile_prefix &&
            !(ost->logfile_prefix = av_strdup(ost->logfile_prefix)))
            exit_program(1);

        if (do_pass) {
            char logfilename[1024];
            FILE *f;

            snprintf(logfilename, sizeof(logfilename), "%s-%d.log",
                     ost->logfile_prefix ? ost->logfile_prefix :
                                           DEFAULT_PASS_LOGFILENAME_PREFIX,
                     i);
            if (!strcmp(ost->enc->name, "libx264")) {
                av_dict_set(&ost->encoder_opts, "stats", logfilename, AV_DICT_DONT_OVERWRITE);
            } else {
                if (video_enc->flags & AV_CODEC_FLAG_PASS2) {
                    char  *logbuffer = read_file(logfilename);

                    if (!logbuffer) {
                        av_log(NULL, AV_LOG_FATAL, "Error reading log file '%s' for pass-2 encoding\n",
                               logfilename);
                        exit_program(1);
                    }
                    video_enc->stats_in = logbuffer;
                }
                if (video_enc->flags & AV_CODEC_FLAG_PASS1) {
                    f = av_fopen_utf8(logfilename, "wb");
                    if (!f) {
                        av_log(NULL, AV_LOG_FATAL,
                               "Cannot write log file '%s' for pass-1 encoding: %s\n",
                               logfilename, strerror(errno));
                        exit_program(1);
                    }
                    ost->logfile = f;
                }
            }
        }

        MATCH_PER_STREAM_OPT(forced_key_frames, str, ost->forced_keyframes, oc, st);
        if (ost->forced_keyframes)
            ost->forced_keyframes = av_strdup(ost->forced_keyframes);

        MATCH_PER_STREAM_OPT(force_fps, i, ost->force_fps, oc, st);

        ost->top_field_first = -1;
        MATCH_PER_STREAM_OPT(top_field_first, i, ost->top_field_first, oc, st);


        ost->avfilter = get_ost_filters(o, oc, ost);
        if (!ost->avfilter)
            exit_program(1);
    } else {
        MATCH_PER_STREAM_OPT(copy_initial_nonkeyframes, i, ost->copy_initial_nonkeyframes, oc ,st);
    }

    if (ost->stream_copy)
        check_streamcopy_filters(o, oc, ost, AVMEDIA_TYPE_VIDEO);

    return ost;
}

static OutputStream *new_audio_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    int n;
    AVStream *st;
    OutputStream *ost;
    AVCodecContext *audio_enc;

    ost = new_output_stream(o, oc, AVMEDIA_TYPE_AUDIO, source_index);
    st  = ost->st;

    audio_enc = ost->enc_ctx;
    audio_enc->codec_type = AVMEDIA_TYPE_AUDIO;

    MATCH_PER_STREAM_OPT(filter_scripts, str, ost->filters_script, oc, st);
    MATCH_PER_STREAM_OPT(filters,        str, ost->filters,        oc, st);

    if (!ost->stream_copy) {
        char *sample_fmt = NULL;

        MATCH_PER_STREAM_OPT(audio_channels, i, audio_enc->channels, oc, st);

        MATCH_PER_STREAM_OPT(sample_fmts, str, sample_fmt, oc, st);
        if (sample_fmt &&
            (audio_enc->sample_fmt = av_get_sample_fmt(sample_fmt)) == AV_SAMPLE_FMT_NONE) {
            av_log(NULL, AV_LOG_FATAL, "Invalid sample format '%s'\n", sample_fmt);
            exit_program(1);
        }

        MATCH_PER_STREAM_OPT(audio_sample_rate, i, audio_enc->sample_rate, oc, st);

        MATCH_PER_STREAM_OPT(apad, str, ost->apad, oc, st);
        ost->apad = av_strdup(ost->apad);

        ost->avfilter = get_ost_filters(o, oc, ost);
        if (!ost->avfilter)
            exit_program(1);

        /* check for channel mapping for this audio stream */
        for (n = 0; n < o->nb_audio_channel_maps; n++) {
            AudioChannelMap *map = &o->audio_channel_maps[n];
            if ((map->ofile_idx   == -1 || ost->file_index == map->ofile_idx) &&
                (map->ostream_idx == -1 || ost->st->index  == map->ostream_idx)) {
                InputStream *ist;

                if (map->channel_idx == -1) {
                    ist = NULL;
                } else if (ost->source_index < 0) {
                    av_log(NULL, AV_LOG_FATAL, "Cannot determine input stream for channel mapping %d.%d\n",
                           ost->file_index, ost->st->index);
                    continue;
                } else {
                    ist = input_streams[ost->source_index];
                }

                if (!ist || (ist->file_index == map->file_idx && ist->st->index == map->stream_idx)) {
                    if (av_reallocp_array(&ost->audio_channels_map,
                                          ost->audio_channels_mapped + 1,
                                          sizeof(*ost->audio_channels_map)
                                          ) < 0 )
                        exit_program(1);

                    ost->audio_channels_map[ost->audio_channels_mapped++] = map->channel_idx;
                }
            }
        }
    }

    if (ost->stream_copy)
        check_streamcopy_filters(o, oc, ost, AVMEDIA_TYPE_AUDIO);

    return ost;
}

static OutputStream *new_data_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    OutputStream *ost;

    ost = new_output_stream(o, oc, AVMEDIA_TYPE_DATA, source_index);
    if (!ost->stream_copy) {
        av_log(NULL, AV_LOG_FATAL, "Data stream encoding not supported yet (only streamcopy)\n");
        exit_program(1);
    }

    return ost;
}

static OutputStream *new_unknown_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    OutputStream *ost;

    ost = new_output_stream(o, oc, AVMEDIA_TYPE_UNKNOWN, source_index);
    if (!ost->stream_copy) {
        av_log(NULL, AV_LOG_FATAL, "Unknown stream encoding not supported yet (only streamcopy)\n");
        exit_program(1);
    }

    return ost;
}

static OutputStream *new_attachment_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    OutputStream *ost = new_output_stream(o, oc, AVMEDIA_TYPE_ATTACHMENT, source_index);
    ost->stream_copy = 1;
    ost->finished    = 1;
    return ost;
}

static OutputStream *new_subtitle_stream(OptionsContext *o, AVFormatContext *oc, int source_index)
{
    AVStream *st;
    OutputStream *ost;
    AVCodecContext *subtitle_enc;

    ost = new_output_stream(o, oc, AVMEDIA_TYPE_SUBTITLE, source_index);
    st  = ost->st;
    subtitle_enc = ost->enc_ctx;

    subtitle_enc->codec_type = AVMEDIA_TYPE_SUBTITLE;

    MATCH_PER_STREAM_OPT(copy_initial_nonkeyframes, i, ost->copy_initial_nonkeyframes, oc, st);

    if (!ost->stream_copy) {
        char *frame_size = NULL;

        MATCH_PER_STREAM_OPT(frame_sizes, str, frame_size, oc, st);
        if (frame_size && av_parse_video_size(&subtitle_enc->width, &subtitle_enc->height, frame_size) < 0) {
            av_log(NULL, AV_LOG_FATAL, "Invalid frame size: %s.\n", frame_size);
            exit_program(1);
        }
    }

    return ost;
}

/* arg format is "output-stream-index:streamid-value". */
static int opt_streamid(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    int idx;
    char *p;
    char idx_str[16];

    av_strlcpy(idx_str, arg, sizeof(idx_str));
    p = strchr(idx_str, ':');
    if (!p) {
        av_log(NULL, AV_LOG_FATAL,
               "Invalid value '%s' for option '%s', required syntax is 'index:value'\n",
               arg, opt);
        exit_program(1);
    }
    *p++ = '\0';
    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, MAX_STREAMS-1);
    o->streamid_map = grow_array(o->streamid_map, sizeof(*o->streamid_map), &o->nb_streamid_map, idx+1);
    o->streamid_map[idx] = parse_number_or_die(opt, p, OPT_INT, 0, INT_MAX);
    return 0;
}

static int copy_chapters(InputFile *ifile, OutputFile *ofile, int copy_metadata)
{
    AVFormatContext *is = ifile->ctx;
    AVFormatContext *os = ofile->ctx;
    AVChapter **tmp;
    int i;

    tmp = av_realloc_f(os->chapters, is->nb_chapters + os->nb_chapters, sizeof(*os->chapters));
    if (!tmp)
        return AVERROR(ENOMEM);
    os->chapters = tmp;

    for (i = 0; i < is->nb_chapters; i++) {
        AVChapter *in_ch = is->chapters[i], *out_ch;
        int64_t start_time = (ofile->start_time == AV_NOPTS_VALUE) ? 0 : ofile->start_time;
        int64_t ts_off   = av_rescale_q(start_time - ifile->ts_offset,
                                       AV_TIME_BASE_Q, in_ch->time_base);
        int64_t rt       = (ofile->recording_time == INT64_MAX) ? INT64_MAX :
                           av_rescale_q(ofile->recording_time, AV_TIME_BASE_Q, in_ch->time_base);


        if (in_ch->end < ts_off)
            continue;
        if (rt != INT64_MAX && in_ch->start > rt + ts_off)
            break;

        out_ch = av_mallocz(sizeof(AVChapter));
        if (!out_ch)
            return AVERROR(ENOMEM);

        out_ch->id        = in_ch->id;
        out_ch->time_base = in_ch->time_base;
        out_ch->start     = FFMAX(0,  in_ch->start - ts_off);
        out_ch->end       = FFMIN(rt, in_ch->end   - ts_off);

        if (copy_metadata)
            av_dict_copy(&out_ch->metadata, in_ch->metadata, 0);

        os->chapters[os->nb_chapters++] = out_ch;
    }
    return 0;
}

static int read_ffserver_streams(OptionsContext *o, AVFormatContext *s, const char *filename)
{
    int i, err;
    AVFormatContext *ic = avformat_alloc_context();

    ic->interrupt_callback = int_cb;
    err = avformat_open_input(&ic, filename, NULL, NULL);
    if (err < 0)
        return err;
    /* copy stream format */
    for(i=0;i<ic->nb_streams;i++) {
        AVStream *st;
        OutputStream *ost;
        AVCodec *codec;
        const char *enc_config;

        codec = avcodec_find_encoder(ic->streams[i]->codec->codec_id);
        if (!codec) {
            av_log(s, AV_LOG_ERROR, "no encoder found for codec id %i\n", ic->streams[i]->codec->codec_id);
            return AVERROR(EINVAL);
        }
        if (codec->type == AVMEDIA_TYPE_AUDIO)
            opt_audio_codec(o, "c:a", codec->name);
        else if (codec->type == AVMEDIA_TYPE_VIDEO)
            opt_video_codec(o, "c:v", codec->name);
        ost   = new_output_stream(o, s, codec->type, -1);
        st    = ost->st;

        avcodec_get_context_defaults3(st->codec, codec);
        enc_config = av_stream_get_recommended_encoder_configuration(ic->streams[i]);
        if (enc_config) {
            AVDictionary *opts = NULL;
            av_dict_parse_string(&opts, enc_config, "=", ",", 0);
            av_opt_set_dict2(st->codec, &opts, AV_OPT_SEARCH_CHILDREN);
            av_dict_free(&opts);
        }

        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO && !ost->stream_copy)
            choose_sample_fmt(st, codec);
        else if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && !ost->stream_copy)
            choose_pixel_fmt(st, st->codec, codec, st->codec->pix_fmt);
        avcodec_copy_context(ost->enc_ctx, st->codec);
        if (enc_config)
            av_dict_parse_string(&ost->encoder_opts, enc_config, "=", ",", 0);
    }

    avformat_close_input(&ic);
    return err;
}

static void init_output_filter(OutputFilter *ofilter, OptionsContext *o,
                               AVFormatContext *oc)
{
    OutputStream *ost;

    switch (ofilter->type) {
    case AVMEDIA_TYPE_VIDEO: ost = new_video_stream(o, oc, -1); break;
    case AVMEDIA_TYPE_AUDIO: ost = new_audio_stream(o, oc, -1); break;
    default:
        av_log(NULL, AV_LOG_FATAL, "Only video and audio filters are supported "
               "currently.\n");
        exit_program(1);
    }

    ost->source_index = -1;
    ost->filter       = ofilter;

    ofilter->ost      = ost;

    if (ost->stream_copy) {
        av_log(NULL, AV_LOG_ERROR, "Streamcopy requested for output stream %d:%d, "
               "which is fed from a complex filtergraph. Filtering and streamcopy "
               "cannot be used together.\n", ost->file_index, ost->index);
        exit_program(1);
    }

    if (ost->avfilter && (ost->filters || ost->filters_script)) {
        const char *opt = ost->filters ? "-vf/-af/-filter" : "-filter_script";
        av_log(NULL, AV_LOG_ERROR,
               "%s '%s' was specified through the %s option "
               "for output stream %d:%d, which is fed from a complex filtergraph.\n"
               "%s and -filter_complex cannot be used together for the same stream.\n",
               ost->filters ? "Filtergraph" : "Filtergraph script",
               ost->filters ? ost->filters : ost->filters_script,
               opt, ost->file_index, ost->index, opt);
        exit_program(1);
    }

    avfilter_inout_free(&ofilter->out_tmp);
}

static int init_complex_filters(void)
{
    int i, ret = 0;

    for (i = 0; i < nb_filtergraphs; i++) {
        ret = init_complex_filtergraph(filtergraphs[i]);
        if (ret < 0)
            return ret;
    }
    return 0;
}

static int configure_complex_filters(void)
{
    int i, ret = 0;

    for (i = 0; i < nb_filtergraphs; i++)
        if (!filtergraphs[i]->graph &&
            (ret = configure_filtergraph(filtergraphs[i])) < 0)
            return ret;
    return 0;
}

static int open_output_file(OptionsContext *o, const char *filename)
{
    AVFormatContext *oc;
    int i, j, err;
    AVOutputFormat *file_oformat;
    OutputFile *of;
    OutputStream *ost;
    InputStream  *ist;
    AVDictionary *unused_opts = NULL;
    AVDictionaryEntry *e = NULL;


    if (o->stop_time != INT64_MAX && o->recording_time != INT64_MAX) {
        o->stop_time = INT64_MAX;
        av_log(NULL, AV_LOG_WARNING, "-t and -to cannot be used together; using -t.\n");
    }

    if (o->stop_time != INT64_MAX && o->recording_time == INT64_MAX) {
        int64_t start_time = o->start_time == AV_NOPTS_VALUE ? 0 : o->start_time;
        if (o->stop_time <= start_time) {
            av_log(NULL, AV_LOG_ERROR, "-to value smaller than -ss; aborting.\n");
            exit_program(1);
        } else {
            o->recording_time = o->stop_time - start_time;
        }
    }

    GROW_ARRAY(output_files, nb_output_files);
    of = av_mallocz(sizeof(*of));
    if (!of)
        exit_program(1);
    output_files[nb_output_files - 1] = of;

    of->ost_index      = nb_output_streams;
    of->recording_time = o->recording_time;
    of->start_time     = o->start_time;
    of->limit_filesize = o->limit_filesize;
    of->shortest       = o->shortest;
    av_dict_copy(&of->opts, o->g->format_opts, 0);

    if (!strcmp(filename, "-"))
        filename = "pipe:";

    err = avformat_alloc_output_context2(&oc, NULL, o->format, filename);
    if (!oc) {
        print_error(filename, err);
        exit_program(1);
    }

    of->ctx = oc;
    if (o->recording_time != INT64_MAX)
        oc->duration = o->recording_time;

    file_oformat= oc->oformat;
    oc->interrupt_callback = int_cb;

    /* create streams for all unlabeled output pads */
    for (i = 0; i < nb_filtergraphs; i++) {
        FilterGraph *fg = filtergraphs[i];
        for (j = 0; j < fg->nb_outputs; j++) {
            OutputFilter *ofilter = fg->outputs[j];

            if (!ofilter->out_tmp || ofilter->out_tmp->name)
                continue;

            switch (ofilter->type) {
            case AVMEDIA_TYPE_VIDEO:    o->video_disable    = 1; break;
            case AVMEDIA_TYPE_AUDIO:    o->audio_disable    = 1; break;
            case AVMEDIA_TYPE_SUBTITLE: o->subtitle_disable = 1; break;