/**
* First part of subpacket decoding:
* decode raw stream bytes and read gain info.
*
* @param q pointer to the COOKContext
* @param inbuffer pointer to raw stream data
* @param gains_ptr array of current/prev gain pointers
*/
static inline void decode_bytes_and_gain(COOKContext *q, COOKSubpacket *p,
const uint8_t *inbuffer,
cook_gains *gains_ptr)
{
int offset;
offset = decode_bytes(inbuffer, q->decoded_bytes_buffer,
p->bits_per_subpacket / 8);
init_get_bits(&q->gb, q->decoded_bytes_buffer + offset,
p->bits_per_subpacket);
decode_gain_info(&q->gb, gains_ptr->now);
/* Swap current and previous gains */
FFSWAP(int *, gains_ptr->now, gains_ptr->previous);
}
static int decode_subpacket(COOKContext *q, uint8_t *inbuffer,
int sub_packet_size, int16_t *outbuffer) {
int i,j;
int value;
float* tmp_ptr;
/* packet dump */
// for (i=0 ; i<sub_packet_size ; i++) {
// av_log(NULL, AV_LOG_ERROR, "%02x", inbuffer[i]);
// }
// av_log(NULL, AV_LOG_ERROR, "\n");
decode_bytes(inbuffer, q->decoded_bytes_buffer, sub_packet_size);
init_get_bits(&q->gb, q->decoded_bytes_buffer, sub_packet_size*8);
decode_gain_info(&q->gb, &q->gain_current);
if(q->nb_channels==2 && q->joint_stereo==1){
joint_decode(q, q->decode_buf_ptr[0], q->decode_buf_ptr[2]);
/* Swap buffer pointers. */
tmp_ptr = q->decode_buf_ptr[1];
q->decode_buf_ptr[1] = q->decode_buf_ptr[0];
q->decode_buf_ptr[0] = tmp_ptr;
tmp_ptr = q->decode_buf_ptr[3];
q->decode_buf_ptr[3] = q->decode_buf_ptr[2];
q->decode_buf_ptr[2] = tmp_ptr;
/* FIXME: Rethink the gainbuffer handling, maybe a rename?
now/previous swap */
q->gain_now_ptr = &q->gain_now;
q->gain_previous_ptr = &q->gain_previous;
for (i=0 ; i<q->nb_channels ; i++){
cook_imlt(q, q->decode_buf_ptr[i*2], q->mono_mdct_output, q->mlt_tmp);
gain_compensate(q, q->mono_mdct_output, q->gain_now_ptr,
q->gain_previous_ptr, q->previous_buffer_ptr[0]);
/* Swap out the previous buffer. */
tmp_ptr = q->previous_buffer_ptr[0];
q->previous_buffer_ptr[0] = q->previous_buffer_ptr[1];
q->previous_buffer_ptr[1] = tmp_ptr;
/* Clip and convert the floats to 16 bits. */
for (j=0 ; j<q->samples_per_frame ; j++){
value = lrintf(q->mono_mdct_output[j]);
if(value < -32768) value = -32768;
else if(value > 32767) value = 32767;
outbuffer[2*j+i] = value;
}
}
memcpy(&q->gain_now, &q->gain_previous, sizeof(COOKgain));
memcpy(&q->gain_previous, &q->gain_current, sizeof(COOKgain));
} else if (q->nb_channels==2 && q->joint_stereo==0) {
/* channel 0 */
mono_decode(q, q->decode_buf_ptr2[0]);
tmp_ptr = q->decode_buf_ptr2[0];
q->decode_buf_ptr2[0] = q->decode_buf_ptr2[1];
q->decode_buf_ptr2[1] = tmp_ptr;
memcpy(&q->gain_channel1[0], &q->gain_current ,sizeof(COOKgain));
q->gain_now_ptr = &q->gain_channel1[0];
q->gain_previous_ptr = &q->gain_channel1[1];
cook_imlt(q, q->decode_buf_ptr2[0], q->mono_mdct_output,q->mlt_tmp);
gain_compensate(q, q->mono_mdct_output, q->gain_now_ptr,
q->gain_previous_ptr, q->mono_previous_buffer1);
memcpy(&q->gain_channel1[1], &q->gain_channel1[0],sizeof(COOKgain));
for (j=0 ; j<q->samples_per_frame ; j++){
value = lrintf(q->mono_mdct_output[j]);
if(value < -32768) value = -32768;
else if(value > 32767) value = 32767;
outbuffer[2*j+1] = value;
}
/* channel 1 */
//av_log(NULL,AV_LOG_ERROR,"bits = %d\n",get_bits_count(&q->gb));
init_get_bits(&q->gb, q->decoded_bytes_buffer, sub_packet_size*8+q->bits_per_subpacket);
q->gain_now_ptr = &q->gain_channel2[0];
q->gain_previous_ptr = &q->gain_channel2[1];
decode_gain_info(&q->gb, &q->gain_channel2[0]);
mono_decode(q, q->decode_buf_ptr[0]);
tmp_ptr = q->decode_buf_ptr[0];
q->decode_buf_ptr[0] = q->decode_buf_ptr[1];
q->decode_buf_ptr[1] = tmp_ptr;
cook_imlt(q, q->decode_buf_ptr[0], q->mono_mdct_output,q->mlt_tmp);
gain_compensate(q, q->mono_mdct_output, q->gain_now_ptr,
q->gain_previous_ptr, q->mono_previous_buffer2);
/* Swap out the previous buffer. */
tmp_ptr = q->previous_buffer_ptr[0];
q->previous_buffer_ptr[0] = q->previous_buffer_ptr[1];
q->previous_buffer_ptr[1] = tmp_ptr;
memcpy(&q->gain_channel2[1], &q->gain_channel2[0] ,sizeof(COOKgain));
for (j=0 ; j<q->samples_per_frame ; j++){
value = lrintf(q->mono_mdct_output[j]);
if(value < -32768) value = -32768;
else if(value > 32767) value = 32767;
outbuffer[2*j] = value;
}
} else {
mono_decode(q, q->decode_buf_ptr[0]);
/* Swap buffer pointers. */
tmp_ptr = q->decode_buf_ptr[1];
q->decode_buf_ptr[1] = q->decode_buf_ptr[0];
q->decode_buf_ptr[0] = tmp_ptr;
/* FIXME: Rethink the gainbuffer handling, maybe a rename?
now/previous swap */
q->gain_now_ptr = &q->gain_now;
q->gain_previous_ptr = &q->gain_previous;
cook_imlt(q, q->decode_buf_ptr[0], q->mono_mdct_output,q->mlt_tmp);
gain_compensate(q, q->mono_mdct_output, q->gain_now_ptr,
q->gain_previous_ptr, q->mono_previous_buffer1);
/* Clip and convert the floats to 16 bits */
for (j=0 ; j<q->samples_per_frame ; j++){
value = lrintf(q->mono_mdct_output[j]);
if(value < -32768) value = -32768;
else if(value > 32767) value = 32767;
outbuffer[j] = value;
}
memcpy(&q->gain_now, &q->gain_previous, sizeof(COOKgain));
memcpy(&q->gain_previous, &q->gain_current, sizeof(COOKgain));
}
return q->samples_per_frame * sizeof(int16_t);
}
