cmdutils.c

        if (p)
            switch (check_stream_specifier(s, st, p + 1)) {
            case  1: *p = 0; break;
            case  0:         continue;
            default:         exit_program(1);
            }

        if (av_opt_find(&cc, t->key, NULL, flags, AV_OPT_SEARCH_FAKE_OBJ) ||
            !codec ||
            (codec->priv_class &&
             av_opt_find(&codec->priv_class, t->key, NULL, flags,
                         AV_OPT_SEARCH_FAKE_OBJ)))
            av_dict_set(&ret, t->key, t->value, 0);
        else if (t->key[0] == prefix &&
                 av_opt_find(&cc, t->key + 1, NULL, flags,
                             AV_OPT_SEARCH_FAKE_OBJ))
            av_dict_set(&ret, t->key + 1, t->value, 0);

        if (p)
            *p = ':';
    }
    return ret;
}

AVDictionary **setup_find_stream_info_opts(AVFormatContext *s,
                                           AVDictionary *codec_opts)
{
    int i;
    AVDictionary **opts;

    if (!s->nb_streams)
        return NULL;
    opts = av_mallocz_array(s->nb_streams, sizeof(*opts));
    if (!opts) {
        av_log(NULL, AV_LOG_ERROR,
               "Could not alloc memory for stream options.\n");
        return NULL;
    }
    for (i = 0; i < s->nb_streams; i++)
        opts[i] = filter_codec_opts(codec_opts, s->streams[i]->codec->codec_id,
                                    s, s->streams[i], NULL);
    return opts;
}

void *grow_array(void *array, int elem_size, int *size, int new_size)
{
    if (new_size >= INT_MAX / elem_size) {
        av_log(NULL, AV_LOG_ERROR, "Array too big.\n");
        exit_program(1);
    }
    if (*size < new_size) {
        uint8_t *tmp = av_realloc_array(array, new_size, elem_size);
        if (!tmp) {
            av_log(NULL, AV_LOG_ERROR, "Could not alloc buffer.\n");
            exit_program(1);
        }
        memset(tmp + *size*elem_size, 0, (new_size-*size) * elem_size);
        *size = new_size;
        return tmp;
    }
    return array;
}

double get_rotation(AVStream *st)
{
    AVDictionaryEntry *rotate_tag = av_dict_get(st->metadata, "rotate", NULL, 0);
    uint8_t* displaymatrix = av_stream_get_side_data(st,
                                                     AV_PKT_DATA_DISPLAYMATRIX, NULL);
    double theta = 0;

    if (rotate_tag && *rotate_tag->value && strcmp(rotate_tag->value, "0")) {
        char *tail;
        theta = av_strtod(rotate_tag->value, &tail);
        if (*tail)
            theta = 0;
    }
    if (displaymatrix && !theta)
        theta = -av_display_rotation_get((int32_t*) displaymatrix);

    theta -= 360*floor(theta/360 + 0.9/360);

    if (fabs(theta - 90*round(theta/90)) > 2)
        av_log(NULL, AV_LOG_WARNING, "Odd rotation angle.\n"
               "If you want to help, upload a sample "
               "of this file to ftp://upload.ffmpeg.org/incoming/ "
               "and contact the ffmpeg-devel mailing list. (ffmpeg-devel@ffmpeg.org)");

    return theta;
}

#if CONFIG_AVDEVICE
static int print_device_sources(AVInputFormat *fmt, AVDictionary *opts)
{
    int ret, i;
    AVDeviceInfoList *device_list = NULL;

    if (!fmt || !fmt->priv_class  || !AV_IS_INPUT_DEVICE(fmt->priv_class->category))
        return AVERROR(EINVAL);

    printf("Audo-detected sources for %s:\n", fmt->name);
    if (!fmt->get_device_list) {
        ret = AVERROR(ENOSYS);
        printf("Cannot list sources. Not implemented.\n");
        goto fail;
    }

    if ((ret = avdevice_list_input_sources(fmt, NULL, opts, &device_list)) < 0) {
        printf("Cannot list sources.\n");
        goto fail;
    }

    for (i = 0; i < device_list->nb_devices; i++) {
        printf("%s %s [%s]\n", device_list->default_device == i ? "*" : " ",
               device_list->devices[i]->device_name, device_list->devices[i]->device_description);
    }

  fail:
    avdevice_free_list_devices(&device_list);
    return ret;
}

static int print_device_sinks(AVOutputFormat *fmt, AVDictionary *opts)
{
    int ret, i;
    AVDeviceInfoList *device_list = NULL;

    if (!fmt || !fmt->priv_class  || !AV_IS_OUTPUT_DEVICE(fmt->priv_class->category))
        return AVERROR(EINVAL);

    printf("Audo-detected sinks for %s:\n", fmt->name);
    if (!fmt->get_device_list) {
        ret = AVERROR(ENOSYS);
        printf("Cannot list sinks. Not implemented.\n");
        goto fail;
    }

    if ((ret = avdevice_list_output_sinks(fmt, NULL, opts, &device_list)) < 0) {
        printf("Cannot list sinks.\n");
        goto fail;
    }

    for (i = 0; i < device_list->nb_devices; i++) {
        printf("%s %s [%s]\n", device_list->default_device == i ? "*" : " ",
               device_list->devices[i]->device_name, device_list->devices[i]->device_description);
    }

  fail:
    avdevice_free_list_devices(&device_list);
    return ret;
}

static int show_sinks_sources_parse_arg(const char *arg, char **dev, AVDictionary **opts)
{
    int ret;
    if (arg) {
        char *opts_str = NULL;
        av_assert0(dev && opts);
        *dev = av_strdup(arg);
        if (!*dev)
            return AVERROR(ENOMEM);
        if ((opts_str = strchr(*dev, ','))) {
            *(opts_str++) = '\0';
            if (opts_str[0] && ((ret = av_dict_parse_string(opts, opts_str, "=", ":", 0)) < 0)) {
                av_freep(dev);
                return ret;
            }
        }
    } else
        printf("\nDevice name is not provided.\n"
                "You can pass devicename[,opt1=val1[,opt2=val2...]] as an argument.\n\n");
    return 0;
}

int show_sources(void *optctx, const char *opt, const char *arg)
{
    AVInputFormat *fmt = NULL;
    char *dev = NULL;
    AVDictionary *opts = NULL;
    int ret = 0;
    int error_level = av_log_get_level();

    av_log_set_level(AV_LOG_ERROR);

    if ((ret = show_sinks_sources_parse_arg(arg, &dev, &opts)) < 0)
        goto fail;

    do {
        fmt = av_input_audio_device_next(fmt);
        if (fmt) {
            if (!strcmp(fmt->name, "lavfi"))
                continue; //it's pointless to probe lavfi
            if (dev && !av_match_name(dev, fmt->name))
                continue;
            print_device_sources(fmt, opts);
        }
    } while (fmt);
    do {
        fmt = av_input_video_device_next(fmt);
        if (fmt) {
            if (dev && !av_match_name(dev, fmt->name))
                continue;
            print_device_sources(fmt, opts);
        }
    } while (fmt);
  fail:
    av_dict_free(&opts);
    av_free(dev);
    av_log_set_level(error_level);
    return ret;
}

int show_sinks(void *optctx, const char *opt, const char *arg)
{
    AVOutputFormat *fmt = NULL;
    char *dev = NULL;
    AVDictionary *opts = NULL;
    int ret = 0;
    int error_level = av_log_get_level();

    av_log_set_level(AV_LOG_ERROR);

    if ((ret = show_sinks_sources_parse_arg(arg, &dev, &opts)) < 0)
        goto fail;

    do {
        fmt = av_output_audio_device_next(fmt);
        if (fmt) {
            if (dev && !av_match_name(dev, fmt->name))
                continue;
            print_device_sinks(fmt, opts);
        }
    } while (fmt);
    do {
        fmt = av_output_video_device_next(fmt);
        if (fmt) {
            if (dev && !av_match_name(dev, fmt->name))
                continue;
            print_device_sinks(fmt, opts);
        }
    } while (fmt);
  fail:
    av_dict_free(&opts);
    av_free(dev);
    av_log_set_level(error_level);
    return ret;
}

#endif