utils.c

    { "sxga",     1280,1024 },
    { "qsxga",    2560,2048 },
    { "hsxga",    5120,4096 },
    { "wvga",      852, 480 },
    { "wxga",     1366, 768 },
    { "wsxga",    1600,1024 },
    { "wuxga",    1920,1200 },
    { "woxga",    2560,1600 },
    { "wqsxga",   3200,2048 },
    { "wquxga",   3840,2400 },
    { "whsxga",   6400,4096 },
    { "whuxga",   7680,4800 },
    { "cga",       320, 200 },
    { "ega",       640, 350 },
    { "hd480",     852, 480 },
    { "hd720",    1280, 720 },
    { "hd1080",   1920,1080 },
};

static const VideoFrameRateAbbr video_frame_rate_abbrs[]= {
    { "ntsc",      30000, 1001 },
    { "pal",          25,    1 },
    { "qntsc",     30000, 1001 }, /* VCD compliant NTSC */
    { "qpal",         25,    1 }, /* VCD compliant PAL */
    { "sntsc",     30000, 1001 }, /* square pixel NTSC */
    { "spal",         25,    1 }, /* square pixel PAL */
    { "film",         24,    1 },
    { "ntsc-film", 24000, 1001 },
};

int av_parse_video_frame_size(int *width_ptr, int *height_ptr, const char *str)
{
    int i;
    int n = FF_ARRAY_ELEMS(video_frame_size_abbrs);
    char *p;
    int frame_width = 0, frame_height = 0;

    for(i=0;i<n;i++) {
        if (!strcmp(video_frame_size_abbrs[i].abbr, str)) {
            frame_width = video_frame_size_abbrs[i].width;
            frame_height = video_frame_size_abbrs[i].height;
            break;
        }
    }
    if (i == n) {
        p = str;
        frame_width = strtol(p, &p, 10);
        if (*p)
            p++;
        frame_height = strtol(p, &p, 10);
    }
    if (frame_width <= 0 || frame_height <= 0)
        return -1;
    *width_ptr = frame_width;
    *height_ptr = frame_height;
    return 0;
}

int av_parse_video_frame_rate(AVRational *frame_rate, const char *arg)
{
    int i;
    int n = FF_ARRAY_ELEMS(video_frame_rate_abbrs);
    char* cp;

    /* First, we check our abbreviation table */
    for (i = 0; i < n; ++i)
         if (!strcmp(video_frame_rate_abbrs[i].abbr, arg)) {
             frame_rate->num = video_frame_rate_abbrs[i].rate_num;
             frame_rate->den = video_frame_rate_abbrs[i].rate_den;
             return 0;
         }

    /* Then, we try to parse it as fraction */
    cp = strchr(arg, '/');
    if (!cp)
        cp = strchr(arg, ':');
    if (cp) {
        char* cpp;
        frame_rate->num = strtol(arg, &cpp, 10);
        if (cpp != arg || cpp == cp)
            frame_rate->den = strtol(cp+1, &cpp, 10);
        else
           frame_rate->num = 0;
    }
    else {
        /* Finally we give up and parse it as double */
        AVRational time_base = av_d2q(strtod(arg, 0), 1001000);
        frame_rate->den = time_base.den;
        frame_rate->num = time_base.num;
    }
    if (!frame_rate->num || !frame_rate->den)
        return -1;
    else
        return 0;
}

void ff_log_missing_feature(void *avc, const char *feature, int want_sample)
{
    av_log(avc, AV_LOG_WARNING, "%s not implemented. Update your FFmpeg "
            "version to the newest one from SVN. If the problem still "
            "occurs, it means that your file has a feature which has not "
            "been implemented.", feature);
    if(want_sample)
        ff_log_ask_for_sample(avc, NULL);
    else
        av_log(avc, AV_LOG_WARNING, "\n");
}

void ff_log_ask_for_sample(void *avc, const char *msg)
{
    if (msg)
        av_log(avc, AV_LOG_WARNING, "%s ", msg);
    av_log(avc, AV_LOG_WARNING, "If you want to help, upload a sample "
            "of this file to ftp://upload.ffmpeg.org/MPlayer/incoming/ "
            "and contact the ffmpeg-devel mailing list.\n");
}