avconv_opt.c

            av_log(NULL, AV_LOG_FATAL, "Invalid framerate value: %s\n", frame_rate);
            exit(1);
        }

        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(1);
        }

        MATCH_PER_STREAM_OPT(frame_aspect_ratios, str, frame_aspect_ratio, oc, st);
        if (frame_aspect_ratio)
            ost->frame_aspect_ratio = parse_frame_aspect_ratio(frame_aspect_ratio);

        MATCH_PER_STREAM_OPT(frame_pix_fmts, str, frame_pix_fmt, oc, st);
        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(1);
        }
        st->sample_aspect_ratio = video_enc->sample_aspect_ratio;

        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(1);
            }
            parse_matrix_coeffs(video_enc->intra_matrix, 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(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(1);
            }
            video_enc->rc_override =
                av_realloc(video_enc->rc_override,
                           sizeof(RcOverride) * (i + 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;
        video_enc->intra_dc_precision = intra_dc_precision - 8;

        /* two pass mode */
        MATCH_PER_STREAM_OPT(pass, i, do_pass, oc, st);
        if (do_pass) {
            if (do_pass == 1) {
                video_enc->flags |= CODEC_FLAG_PASS1;
            } else {
                video_enc->flags |= CODEC_FLAG_PASS2;
            }
        }

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

        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(1);
    } else {
        MATCH_PER_STREAM_OPT(copy_initial_nonkeyframes, i, ost->copy_initial_nonkeyframes, oc ,st);
    }

    return ost;
}

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

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

    audio_enc = st->codec;
    audio_enc->codec_type = AVMEDIA_TYPE_AUDIO;

    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(1);
        }

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

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

    return ost;
}

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

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

    return ost;
}

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

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

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

    subtitle_enc->codec_type = AVMEDIA_TYPE_SUBTITLE;

    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(1);
    }
    *p++ = '\0';
    idx = parse_number_or_die(opt, idx_str, OPT_INT, 0, INT_MAX);
    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(os->chapters, sizeof(*os->chapters) * (is->nb_chapters + os->nb_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 ts_off   = av_rescale_q(ofile->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 void init_output_filter(OutputFilter *ofilter, OptionsContext *o,
                               AVFormatContext *oc)
{
    OutputStream *ost;

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

    if (configure_output_filter(ofilter->graph, ofilter, ofilter->out_tmp) < 0) {
        av_log(NULL, AV_LOG_FATAL, "Error configuring filter.\n");
        exit(1);
    }
    avfilter_inout_free(&ofilter->out_tmp);
}

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 (configure_complex_filters() < 0) {
        av_log(NULL, AV_LOG_FATAL, "Error configuring filters.\n");
        exit(1);
    }

    GROW_ARRAY(output_files, nb_output_files);
    of = av_mallocz(sizeof(*of));
    if (!of)
        exit(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:";

    oc = avformat_alloc_context();
    if (!oc) {
        print_error(filename, AVERROR(ENOMEM));
        exit(1);
    }
    of->ctx = oc;
    if (o->recording_time != INT64_MAX)
        oc->duration = o->recording_time;

    if (o->format) {
        file_oformat = av_guess_format(o->format, NULL, NULL);
        if (!file_oformat) {
            av_log(NULL, AV_LOG_FATAL, "Requested output format '%s' is not a suitable output format\n", o->format);
            exit(1);
        }
    } else {
        file_oformat = av_guess_format(NULL, filename, NULL);
        if (!file_oformat) {
            av_log(NULL, AV_LOG_FATAL, "Unable to find a suitable output format for '%s'\n",
                   filename);
            exit(1);
        }
    }

    oc->oformat = file_oformat;
    oc->interrupt_callback = int_cb;
    av_strlcpy(oc->filename, filename, sizeof(oc->filename));

    /* 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 (avfilter_pad_get_type(ofilter->out_tmp->filter_ctx->output_pads,
                                          ofilter->out_tmp->pad_idx)) {
            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;
            }
            init_output_filter(ofilter, o, oc);
        }
    }

    if (!o->nb_stream_maps) {
        /* pick the "best" stream of each type */
#define NEW_STREAM(type, index)\
        if (index >= 0) {\
            ost = new_ ## type ## _stream(o, oc);\
            ost->source_index = index;\
            ost->sync_ist     = input_streams[index];\
            input_streams[index]->discard = 0;\
            input_streams[index]->st->discard = AVDISCARD_NONE;\
        }

        /* video: highest resolution */
        if (!o->video_disable && oc->oformat->video_codec != AV_CODEC_ID_NONE) {
            int area = 0, idx = -1;
            for (i = 0; i < nb_input_streams; i++) {
                ist = input_streams[i];
                if (ist->st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
                    ist->st->codec->width * ist->st->codec->height > area) {
                    area = ist->st->codec->width * ist->st->codec->height;
                    idx = i;
                }
            }
            NEW_STREAM(video, idx);
        }

        /* audio: most channels */
        if (!o->audio_disable && oc->oformat->audio_codec != AV_CODEC_ID_NONE) {
            int channels = 0, idx = -1;
            for (i = 0; i < nb_input_streams; i++) {
                ist = input_streams[i];
                if (ist->st->codec->codec_type == AVMEDIA_TYPE_AUDIO &&
                    ist->st->codec->channels > channels) {
                    channels = ist->st->codec->channels;
                    idx = i;
                }
            }
            NEW_STREAM(audio, idx);
        }

        /* subtitles: pick first */
        if (!o->subtitle_disable && oc->oformat->subtitle_codec != AV_CODEC_ID_NONE) {
            for (i = 0; i < nb_input_streams; i++)
                if (input_streams[i]->st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
                    NEW_STREAM(subtitle, i);
                    break;
                }
        }
        /* do something with data? */
    } else {
        for (i = 0; i < o->nb_stream_maps; i++) {
            StreamMap *map = &o->stream_maps[i];

            if (map->disabled)
                continue;

            if (map->linklabel) {
                FilterGraph *fg;
                OutputFilter *ofilter = NULL;
                int j, k;

                for (j = 0; j < nb_filtergraphs; j++) {
                    fg = filtergraphs[j];
                    for (k = 0; k < fg->nb_outputs; k++) {
                        AVFilterInOut *out = fg->outputs[k]->out_tmp;
                        if (out && !strcmp(out->name, map->linklabel)) {
                            ofilter = fg->outputs[k];
                            goto loop_end;
                        }
                    }
                }
loop_end:
                if (!ofilter) {
                    av_log(NULL, AV_LOG_FATAL, "Output with label '%s' does not exist "
                           "in any defined filter graph.\n", map->linklabel);
                    exit(1);
                }
                init_output_filter(ofilter, o, oc);
            } else {
                ist = input_streams[input_files[map->file_index]->ist_index + map->stream_index];
                switch (ist->st->codec->codec_type) {
                case AVMEDIA_TYPE_VIDEO:    ost = new_video_stream(o, oc);    break;
                case AVMEDIA_TYPE_AUDIO:    ost = new_audio_stream(o, oc);    break;
                case AVMEDIA_TYPE_SUBTITLE: ost = new_subtitle_stream(o, oc); break;
                case AVMEDIA_TYPE_DATA:     ost = new_data_stream(o, oc);     break;
                case AVMEDIA_TYPE_ATTACHMENT: ost = new_attachment_stream(o, oc); break;
                default:
                    av_log(NULL, AV_LOG_FATAL, "Cannot map stream #%d:%d - unsupported type.\n",
                           map->file_index, map->stream_index);
                    exit(1);
                }

                ost->source_index = input_files[map->file_index]->ist_index + map->stream_index;
                ost->sync_ist     = input_streams[input_files[map->sync_file_index]->ist_index +
                                               map->sync_stream_index];
                ist->discard = 0;
                ist->st->discard = AVDISCARD_NONE;
            }
        }
    }

    /* handle attached files */
    for (i = 0; i < o->nb_attachments; i++) {
        AVIOContext *pb;
        uint8_t *attachment;
        const char *p;
        int64_t len;

        if ((err = avio_open2(&pb, o->attachments[i], AVIO_FLAG_READ, &int_cb, NULL)) < 0) {
            av_log(NULL, AV_LOG_FATAL, "Could not open attachment file %s.\n",
                   o->attachments[i]);
            exit(1);
        }
        if ((len = avio_size(pb)) <= 0) {
            av_log(NULL, AV_LOG_FATAL, "Could not get size of the attachment %s.\n",
                   o->attachments[i]);
            exit(1);
        }
        if (!(attachment = av_malloc(len))) {
            av_log(NULL, AV_LOG_FATAL, "Attachment %s too large to fit into memory.\n",
                   o->attachments[i]);
            exit(1);
        }
        avio_read(pb, attachment, len);

        ost = new_attachment_stream(o, oc);
        ost->stream_copy               = 0;
        ost->source_index              = -1;
        ost->attachment_filename       = o->attachments[i];
        ost->st->codec->extradata      = attachment;
        ost->st->codec->extradata_size = len;

        p = strrchr(o->attachments[i], '/');
        av_dict_set(&ost->st->metadata, "filename", (p && *p) ? p + 1 : o->attachments[i], AV_DICT_DONT_OVERWRITE);
        avio_close(pb);
    }

    /* check if all codec options have been used */
    unused_opts = strip_specifiers(o->g->codec_opts);
    for (i = of->ost_index; i < nb_output_streams; i++) {
        e = NULL;
        while ((e = av_dict_get(output_streams[i]->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);
        if (!option)
            continue;
        if (!(option->flags & AV_OPT_FLAG_ENCODING_PARAM)) {
            av_log(NULL, AV_LOG_ERROR, "Codec AVOption %s (%s) specified for "
                   "output file #%d (%s) is not an encoding option.\n", e->key,
                   option->help ? option->help : "", nb_output_files - 1,
                   filename);
            exit(1);
        }

        av_log(NULL, AV_LOG_WARNING, "Codec AVOption %s (%s) specified for "
               "output 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 encoder "
               "which was not actually used for any stream.\n", e->key,
               option->help ? option->help : "", nb_output_files - 1, filename);
    }
    av_dict_free(&unused_opts);

    /* check filename in case of an image number is expected */
    if (oc->oformat->flags & AVFMT_NEEDNUMBER) {
        if (!av_filename_number_test(oc->filename)) {
            print_error(oc->filename, AVERROR(EINVAL));
            exit(1);
        }
    }

    if (!(oc->oformat->flags & AVFMT_NOFILE)) {
        /* test if it already exists to avoid losing precious files */
        assert_file_overwrite(filename);

        /* open the file */
        if ((err = avio_open2(&oc->pb, filename, AVIO_FLAG_WRITE,
                              &oc->interrupt_callback,
                              &of->opts)) < 0) {
            print_error(filename, err);
            exit(1);
        }
    }

    if (o->mux_preload) {
        uint8_t buf[64];
        snprintf(buf, sizeof(buf), "%d", (int)(o->mux_preload*AV_TIME_BASE));
        av_dict_set(&of->opts, "preload", buf, 0);
    }
    oc->max_delay = (int)(o->mux_max_delay * AV_TIME_BASE);
    oc->flags |= AVFMT_FLAG_NONBLOCK;

    /* copy metadata */
    for (i = 0; i < o->nb_metadata_map; i++) {
        char *p;
        int in_file_index = strtol(o->metadata_map[i].u.str, &p, 0);

        if (in_file_index >= nb_input_files) {
            av_log(NULL, AV_LOG_FATAL, "Invalid input file index %d while processing metadata maps\n", in_file_index);
            exit(1);
        }
        copy_metadata(o->metadata_map[i].specifier, *p ? p + 1 : p, oc,
                      in_file_index >= 0 ?
                      input_files[in_file_index]->ctx : NULL, o);
    }

    /* copy chapters */
    if (o->chapters_input_file >= nb_input_files) {
        if (o->chapters_input_file == INT_MAX) {
            /* copy chapters from the first input file that has them*/
            o->chapters_input_file = -1;
            for (i = 0; i < nb_input_files; i++)
                if (input_files[i]->ctx->nb_chapters) {
                    o->chapters_input_file = i;
                    break;
                }
        } else {
            av_log(NULL, AV_LOG_FATAL, "Invalid input file index %d in chapter mapping.\n",
                   o->chapters_input_file);
            exit(1);
        }
    }
    if (o->chapters_input_file >= 0)
        copy_chapters(input_files[o->chapters_input_file], of,
                      !o->metadata_chapters_manual);

    /* copy global metadata by default */
    if (!o->metadata_global_manual && nb_input_files)
        av_dict_copy(&oc->metadata, input_files[0]->ctx->metadata,
                     AV_DICT_DONT_OVERWRITE);
    if (!o->metadata_streams_manual)
        for (i = of->ost_index; i < nb_output_streams; i++) {
            InputStream *ist;
            if (output_streams[i]->source_index < 0)         /* this is true e.g. for attached files */
                continue;
            ist = input_streams[output_streams[i]->source_index];
            av_dict_copy(&output_streams[i]->st->metadata, ist->st->metadata, AV_DICT_DONT_OVERWRITE);
        }

    /* process manually set metadata */
    for (i = 0; i < o->nb_metadata; i++) {
        AVDictionary **m;
        char type, *val;
        const char *stream_spec;
        int index = 0, j, ret;

        val = strchr(o->metadata[i].u.str, '=');
        if (!val) {
            av_log(NULL, AV_LOG_FATAL, "No '=' character in metadata string %s.\n",
                   o->metadata[i].u.str);
            exit(1);
        }
        *val++ = 0;

        parse_meta_type(o->metadata[i].specifier, &type, &index, &stream_spec);
        if (type == 's') {
            for (j = 0; j < oc->nb_streams; j++) {
                if ((ret = check_stream_specifier(oc, oc->streams[j], stream_spec)) > 0) {
                    av_dict_set(&oc->streams[j]->metadata, o->metadata[i].u.str, *val ? val : NULL, 0);
                } else if (ret < 0)
                    exit(1);
            }
        }
        else {
            switch (type) {
            case 'g':
                m = &oc->metadata;
                break;
            case 'c':
                if (index < 0 || index >= oc->nb_chapters) {
                    av_log(NULL, AV_LOG_FATAL, "Invalid chapter index %d in metadata specifier.\n", index);
                    exit(1);
                }
                m = &oc->chapters[index]->metadata;
                break;
            default:
                av_log(NULL, AV_LOG_FATAL, "Invalid metadata specifier %s.\n", o->metadata[i].specifier);
                exit(1);
            }
            av_dict_set(m, o->metadata[i].u.str, *val ? val : NULL, 0);
        }
    }

    return 0;
}

static int opt_target(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    enum { PAL, NTSC, FILM, UNKNOWN } norm = UNKNOWN;
    static const char *const frame_rates[] = { "25", "30000/1001", "24000/1001" };

    if (!strncmp(arg, "pal-", 4)) {
        norm = PAL;
        arg += 4;
    } else if (!strncmp(arg, "ntsc-", 5)) {
        norm = NTSC;
        arg += 5;
    } else if (!strncmp(arg, "film-", 5)) {
        norm = FILM;
        arg += 5;
    } else {
        /* Try to determine PAL/NTSC by peeking in the input files */
        if (nb_input_files) {
            int i, j, fr;
            for (j = 0; j < nb_input_files; j++) {
                for (i = 0; i < input_files[j]->nb_streams; i++) {
                    AVCodecContext *c = input_files[j]->ctx->streams[i]->codec;
                    if (c->codec_type != AVMEDIA_TYPE_VIDEO)
                        continue;
                    fr = c->time_base.den * 1000 / c->time_base.num;
                    if (fr == 25000) {
                        norm = PAL;
                        break;
                    } else if ((fr == 29970) || (fr == 23976)) {
                        norm = NTSC;
                        break;
                    }
                }
                if (norm != UNKNOWN)
                    break;
            }
        }
        if (norm != UNKNOWN)
            av_log(NULL, AV_LOG_INFO, "Assuming %s for target.\n", norm == PAL ? "PAL" : "NTSC");
    }

    if (norm == UNKNOWN) {
        av_log(NULL, AV_LOG_FATAL, "Could not determine norm (PAL/NTSC/NTSC-Film) for target.\n");
        av_log(NULL, AV_LOG_FATAL, "Please prefix target with \"pal-\", \"ntsc-\" or \"film-\",\n");
        av_log(NULL, AV_LOG_FATAL, "or set a framerate with \"-r xxx\".\n");
        exit(1);
    }

    if (!strcmp(arg, "vcd")) {
        opt_video_codec(o, "c:v", "mpeg1video");
        opt_audio_codec(o, "c:a", "mp2");
        parse_option(o, "f", "vcd", options);

        parse_option(o, "s", norm == PAL ? "352x288" : "352x240", options);
        parse_option(o, "r", frame_rates[norm], options);
        opt_default(NULL, "g", norm == PAL ? "15" : "18");

        opt_default(NULL, "b", "1150000");
        opt_default(NULL, "maxrate", "1150000");
        opt_default(NULL, "minrate", "1150000");
        opt_default(NULL, "bufsize", "327680"); // 40*1024*8;

        opt_default(NULL, "b:a", "224000");
        parse_option(o, "ar", "44100", options);
        parse_option(o, "ac", "2", options);

        opt_default(NULL, "packetsize", "2324");
        opt_default(NULL, "muxrate", "1411200"); // 2352 * 75 * 8;

        /* We have to offset the PTS, so that it is consistent with the SCR.
           SCR starts at 36000, but the first two packs contain only padding
           and the first pack from the other stream, respectively, may also have
           been written before.
           So the real data starts at SCR 36000+3*1200. */
        o->mux_preload = (36000 + 3 * 1200) / 90000.0; // 0.44
    } else if (!strcmp(arg, "svcd")) {

        opt_video_codec(o, "c:v", "mpeg2video");
        opt_audio_codec(o, "c:a", "mp2");
        parse_option(o, "f", "svcd", options);

        parse_option(o, "s", norm == PAL ? "480x576" : "480x480", options);
        parse_option(o, "r", frame_rates[norm], options);
        opt_default(NULL, "g", norm == PAL ? "15" : "18");

        opt_default(NULL, "b", "2040000");
        opt_default(NULL, "maxrate", "2516000");
        opt_default(NULL, "minrate", "0"); // 1145000;
        opt_default(NULL, "bufsize", "1835008"); // 224*1024*8;
        opt_default(NULL, "flags", "+scan_offset");


        opt_default(NULL, "b:a", "224000");
        parse_option(o, "ar", "44100", options);

        opt_default(NULL, "packetsize", "2324");

    } else if (!strcmp(arg, "dvd")) {

        opt_video_codec(o, "c:v", "mpeg2video");
        opt_audio_codec(o, "c:a", "ac3");
        parse_option(o, "f", "dvd", options);

        parse_option(o, "s", norm == PAL ? "720x576" : "720x480", options);
        parse_option(o, "r", frame_rates[norm], options);
        opt_default(NULL, "g", norm == PAL ? "15" : "18");

        opt_default(NULL, "b", "6000000");
        opt_default(NULL, "maxrate", "9000000");
        opt_default(NULL, "minrate", "0"); // 1500000;
        opt_default(NULL, "bufsize", "1835008"); // 224*1024*8;

        opt_default(NULL, "packetsize", "2048");  // from www.mpucoder.com: DVD sectors contain 2048 bytes of data, this is also the size of one pack.
        opt_default(NULL, "muxrate", "10080000"); // from mplex project: data_rate = 1260000. mux_rate = data_rate * 8

        opt_default(NULL, "b:a", "448000");
        parse_option(o, "ar", "48000", options);

    } else if (!strncmp(arg, "dv", 2)) {

        parse_option(o, "f", "dv", options);

        parse_option(o, "s", norm == PAL ? "720x576" : "720x480", options);
        parse_option(o, "pix_fmt", !strncmp(arg, "dv50", 4) ? "yuv422p" :
                          norm == PAL ? "yuv420p" : "yuv411p", options);
        parse_option(o, "r", frame_rates[norm], options);

        parse_option(o, "ar", "48000", options);
        parse_option(o, "ac", "2", options);

    } else {
        av_log(NULL, AV_LOG_ERROR, "Unknown target: %s\n", arg);
        return AVERROR(EINVAL);
    }
    return 0;
}

static int opt_vstats_file(void *optctx, const char *opt, const char *arg)
{
    av_free (vstats_filename);
    vstats_filename = av_strdup (arg);
    return 0;
}

static int opt_vstats(void *optctx, const char *opt, const char *arg)
{
    char filename[40];
    time_t today2 = time(NULL);
    struct tm *today = localtime(&today2);

    snprintf(filename, sizeof(filename), "vstats_%02d%02d%02d.log", today->tm_hour, today->tm_min,
             today->tm_sec);
    return opt_vstats_file(NULL, opt, filename);
}

static int opt_video_frames(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "frames:v", arg, options);
}

static int opt_audio_frames(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "frames:a", arg, options);
}

static int opt_data_frames(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "frames:d", arg, options);
}

static int opt_video_tag(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "tag:v", arg, options);
}

static int opt_audio_tag(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "tag:a", arg, options);
}

static int opt_subtitle_tag(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "tag:s", arg, options);
}

static int opt_video_filters(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "filter:v", arg, options);
}

static int opt_audio_filters(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "filter:a", arg, options);
}

static int opt_vsync(void *optctx, const char *opt, const char *arg)
{
    if      (!av_strcasecmp(arg, "cfr"))         video_sync_method = VSYNC_CFR;
    else if (!av_strcasecmp(arg, "vfr"))         video_sync_method = VSYNC_VFR;
    else if (!av_strcasecmp(arg, "passthrough")) video_sync_method = VSYNC_PASSTHROUGH;

    if (video_sync_method == VSYNC_AUTO)
        video_sync_method = parse_number_or_die("vsync", arg, OPT_INT, VSYNC_AUTO, VSYNC_VFR);
    return 0;
}

int opt_cpuflags(void *optctx, const char *opt, const char *arg)
{
    int flags = av_parse_cpu_flags(arg);

    if (flags < 0)
        return flags;

    av_set_cpu_flags_mask(flags);
    return 0;
}

static int opt_channel_layout(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    char layout_str[32];
    char *stream_str;
    char *ac_str;
    int ret, channels, ac_str_size;
    uint64_t layout;

    layout = av_get_channel_layout(arg);
    if (!layout) {
        av_log(NULL, AV_LOG_ERROR, "Unknown channel layout: %s\n", arg);
        return AVERROR(EINVAL);
    }
    snprintf(layout_str, sizeof(layout_str), "%"PRIu64, layout);
    ret = opt_default(NULL, opt, layout_str);
    if (ret < 0)
        return ret;

    /* set 'ac' option based on channel layout */
    channels = av_get_channel_layout_nb_channels(layout);
    snprintf(layout_str, sizeof(layout_str), "%d", channels);
    stream_str = strchr(opt, ':');
    ac_str_size = 3 + (stream_str ? strlen(stream_str) : 0);
    ac_str = av_mallocz(ac_str_size);
    if (!ac_str)
        return AVERROR(ENOMEM);
    av_strlcpy(ac_str, "ac", 3);
    if (stream_str)
        av_strlcat(ac_str, stream_str, ac_str_size);
    ret = parse_option(o, ac_str, layout_str, options);
    av_free(ac_str);

    return ret;
}

static int opt_audio_qscale(void *optctx, const char *opt, const char *arg)
{
    OptionsContext *o = optctx;
    return parse_option(o, "q:a", arg, options);
}

static int opt_filter_complex(void *optctx, const char *opt, const char *arg)
{
    GROW_ARRAY(filtergraphs, nb_filtergraphs);
    if (!(filtergraphs[nb_filtergraphs - 1] = av_mallocz(sizeof(*filtergraphs[0]))))
        return AVERROR(ENOMEM);
    filtergraphs[nb_filtergraphs - 1]->index      = nb_filtergraphs - 1;
    filtergraphs[nb_filtergraphs - 1]->graph_desc = av_strdup(arg);
    if (!filtergraphs[nb_filtergraphs - 1]->graph_desc)
        return AVERROR(ENOMEM);
    return 0;
}

static int opt_filter_complex_script(void *optctx, const char *opt, const char *arg)
{
    uint8_t *graph_desc = read_file(arg);
    if (!graph_desc)
        return AVERROR(EINVAL);

    GROW_ARRAY(filtergraphs, nb_filtergraphs);
    if (!(filtergraphs[nb_filtergraphs - 1] = av_mallocz(sizeof(*filtergraphs[0]))))
        return AVERROR(ENOMEM);
    filtergraphs[nb_filtergraphs - 1]->index      = nb_filtergraphs - 1;
    filtergraphs[nb_filtergraphs - 1]->graph_desc = graph_desc;
    return 0;
}

void show_help_default(const char *opt, const char *arg)
{
    /* per-file options have at least one of those set */
    const int per_file = OPT_SPEC | OPT_OFFSET | OPT_PERFILE;
    int show_advanced = 0, show_avoptions = 0;

    if (opt && *opt) {
        if (!strcmp(opt, "long"))
            show_advanced = 1;
        else if (!strcmp(opt, "full"))
            show_advanced = show_avoptions = 1;
        else
            av_log(NULL, AV_LOG_ERROR, "Unknown help option '%s'.\n", opt);
    }

    show_usage();

    printf("Getting help:\n"
           "    -h      -- print basic options\n"
           "    -h long -- print more options\n"
           "    -h full -- print all options (including all format and codec specific options, very long)\n"
           "    See man %s for detailed description of the options.\n"
           "\n", program_name);

    show_help_options(options, "Print help / information / capabilities:",
                      OPT_EXIT, 0, 0);

    show_help_options(options, "Global options (affect whole program "
                      "instead of just one file:",
                      0, per_file | OPT_EXIT | OPT_EXPERT, 0);
    if (show_advanced)
        show_help_options(options, "Advanced global options:", OPT_EXPERT,
                          per_file | OPT_EXIT, 0);

    show_help_options(options, "Per-file main options:", 0,
                      OPT_EXPERT | OPT_AUDIO | OPT_VIDEO | OPT_SUBTITLE |
                      OPT_EXIT, per_file);
    if (show_advanced)
        show_help_options(options, "Advanced per-file options:",
                          OPT_EXPERT, OPT_AUDIO | OPT_VIDEO | OPT_SUBTITLE, per_file);

    show_help_options(options, "Video options:",
                      OPT_VIDEO, OPT_EXPERT | OPT_AUDIO, 0);
    if (show_advanced)
        show_help_options(options, "Advanced Video options:",
                          OPT_EXPERT | OPT_VIDEO, OPT_AUDIO, 0);

    show_help_options(options, "Audio options:",
                      OPT_AUDIO, OPT_EXPERT | OPT_VIDEO, 0);
    if (show_advanced)
        show_help_options(options, "Advanced Audio options:",
                          OPT_EXPERT | OPT_AUDIO, OPT_VIDEO, 0);
    show_help_options(options, "Subtitle options:",
                      OPT_SUBTITLE, 0, 0);
    printf("\n");