static int ra144_decode_frame(AVCodecContext * avctx, void *data, int *got_frame_ptr, AVPacket *avpkt) { AVFrame *frame = data; const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2}; unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients uint16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame int i, j; int ret; int16_t *samples; unsigned int energy; RA144Context *ractx = avctx->priv_data; GetBitContext gb; /* get output buffer */ frame->nb_samples = NBLOCKS * BLOCKSIZE; if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } samples = (int16_t *)frame->data[0]; if(buf_size < FRAMESIZE) { av_log(avctx, AV_LOG_ERROR, "Frame too small (%d bytes). Truncated file?\n", buf_size); *got_frame_ptr = 0; return buf_size; } init_get_bits(&gb, buf, FRAMESIZE * 8); for (i = 0; i < LPC_ORDER; i++) lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])]; ff_eval_coefs(ractx->lpc_coef[0], lpc_refl); ractx->lpc_refl_rms[0] = ff_rms(lpc_refl); energy = ff_energy_tab[get_bits(&gb, 5)]; refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy); refl_rms[1] = ff_interp(ractx, block_coefs[1], 2, energy <= ractx->old_energy, ff_t_sqrt(energy*ractx->old_energy) >> 12); refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy); refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy); ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]); for (i=0; i < NBLOCKS; i++) { do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb); for (j=0; j < BLOCKSIZE; j++) *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2); } ractx->old_energy = energy; ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0]; FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]); *got_frame_ptr = 1; return FRAMESIZE; }