more_rbsp_data function is wrong

[alexvazquezfente]

I am using the h264bitstream command to help me writing an h.264 decoder and i think the implementation of function more_rbsp_data() in h264bitstream_data is wrong. The parser is not detecting PPS with transform_8x8_mode_flag = 1 (nor the remaining PPS syntax elements) due to more_rbsp_data() interpreting that bit as the rsbp_stop_bit. Also, sei messages are not correctly parsed. This is a working implementation:

int more_rbsp_data(h264_stream_t* h, bs_t* bs) {

  /* no more data */
  if (bs_eof(bs)) return 0;

  /* no rbsp_stop_bit yet */
  if (bs_peek_u1(bs) == 0) return 1;

  /* next bit is 1, is it the rsbp_stop_bit? only if the rest of bits are 0 */
  bs_t aux;
  bs_clone(&aux, bs);
  bs_skip_u1(&aux);
  while(!bs_eof(&aux)) {
    /* A later bit was 1, it wasn't the rsbp_stop_bit */
    if (bs_read_u1(&aux) == 1) return 1;
  }

  /* All following bits were 0, it was the rsbp_stop_bit */
  return 0;

}

[aizvorski]

Thank you. Fixed per your suggestion: https://github.com/aizvorski/h264bitstream/commit/3e3ad236f8fc506555a8d3e70f9415f87d96a512