Function slice_decode_thread

libavcodec/mpeg12dec.c:1639–1687

}

static int slice_decode_thread(AVCodecContext *c, void *arg)
{
    Mpeg12SliceContext *const s = *(void **) arg;
    const uint8_t *buf  = s->gb.buffer;
    const uint8_t *end  = buf + get_bits_bytesize(&s->gb, 0);
    int mb_y            = s->c.start_mb_y;
    const int field_pic = s->c.picture_structure != PICT_FRAME;

    s->c.er.error_count = (3 * (s->c.end_mb_y - s->c.start_mb_y) * s->c.mb_width) >> field_pic;

    for (;;) {
        uint32_t start_code;
        int ret;

        ret = mpeg_decode_slice(s, mb_y, &buf, end - buf);
        emms_c();
        ff_dlog(c, "ret:%d resync:%d/%d mb:%d/%d ts:%d/%d ec:%d\n",
                ret, s->c.resync_mb_x, s->c.resync_mb_y, s->c.mb_x, s->c.mb_y,
                s->c.start_mb_y, s->c.end_mb_y, s->c.er.error_count);
        if (ret < 0) {
            if (c->err_recognition & AV_EF_EXPLODE)
                return ret;
            if (s->c.resync_mb_x >= 0 && s->c.resync_mb_y >= 0)
                ff_er_add_slice(&s->c.er, s->c.resync_mb_x, s->c.resync_mb_y,
                                s->c.mb_x, s->c.mb_y,
                                ER_AC_ERROR | ER_DC_ERROR | ER_MV_ERROR);
        } else {
            ff_er_add_slice(&s->c.er, s->c.resync_mb_x, s->c.resync_mb_y,
                            s->c.mb_x - 1, s->c.mb_y,
                            ER_AC_END | ER_DC_END | ER_MV_END);
        }

        if (s->c.mb_y == s->c.end_mb_y)
            return 0;

        start_code = -1;
        buf        = avpriv_find_start_code(buf, end, &start_code);
        if (start_code < SLICE_MIN_START_CODE || start_code > SLICE_MAX_START_CODE)
            return AVERROR_INVALIDDATA;
        mb_y       = start_code - SLICE_MIN_START_CODE;
        if (s->c.codec_id != AV_CODEC_ID_MPEG1VIDEO && s->c.mb_height > 2800/16)
            mb_y += (*buf&0xE0)<<2;
        mb_y <<= field_pic;
        if (s->c.picture_structure == PICT_BOTTOM_FIELD)
            mb_y++;
        if (mb_y >= s->c.end_mb_y)
            return AVERROR_INVALIDDATA;
    }
}

/**
 * Handle slice ends.