Function parse_keyframes_index

libavformat/flvdec.c:521–614

}

static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, int64_t max_pos)
{
    FLVContext *flv       = s->priv_data;
    unsigned int timeslen = 0, fileposlen = 0, i;
    char str_val[256];
    int64_t *times         = NULL;
    int64_t *filepositions = NULL;
    int ret                = AVERROR(ENOSYS);
    int64_t initial_pos    = avio_tell(ioc);

    if (flv->keyframe_count > 0) {
        av_log(s, AV_LOG_DEBUG, "keyframes have been parsed\n");
        return 0;
    }
    av_assert0(!flv->keyframe_times);
    av_assert0(!flv->keyframe_filepositions);

    if (s->flags & AVFMT_FLAG_IGNIDX)
        return 0;

    while (avio_tell(ioc) < max_pos - 2 &&
           amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
        int64_t **current_array;
        unsigned int arraylen;
        int factor;

        // Expect array object in context
        if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
            break;

        arraylen = avio_rb32(ioc);
        if (arraylen>>28)
            break;

        if       (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times) {
            current_array = &times;
            timeslen      = arraylen;
            factor = 1000;
        } else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) &&
                   !filepositions) {
            current_array = &filepositions;
            fileposlen    = arraylen;
            factor = 1;
        } else
            // unexpected metatag inside keyframes, will not use such
            // metadata for indexing
            break;

        if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
            ret = AVERROR(ENOMEM);
            goto finish;
        }

        for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
            double d;
            if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
                goto invalid;
            d = av_int2double(avio_rb64(ioc)) * factor;