int init_decoder(void) {
alac_file *alac;
frame_size = fmtp[1]; // stereo samples
sampling_rate = fmtp[11];
int sample_size = fmtp[3];
if (sample_size != 16)
die("only 16-bit samples supported!");
alac = create_alac(sample_size, 2);
if (!alac)
return 1;
decoder_info = alac;
alac->setinfo_max_samples_per_frame = frame_size;
alac->setinfo_7a = fmtp[2];
alac->setinfo_sample_size = sample_size;
alac->setinfo_rice_historymult = fmtp[4];
alac->setinfo_rice_initialhistory = fmtp[5];
alac->setinfo_rice_kmodifier = fmtp[6];
alac->setinfo_7f = fmtp[7];
alac->setinfo_80 = fmtp[8];
alac->setinfo_82 = fmtp[9];
alac->setinfo_86 = fmtp[10];
alac->setinfo_8a_rate = fmtp[11];
allocate_buffers(alac);
return 0;
}
static void init_sound_converter(demux_res_t *demux_res)
{
alac = create_alac(demux_res->sample_size, demux_res->num_channels);
alac_set_info(alac, demux_res->codecdata);
}
/* this is called for each file to process */
enum codec_status codec_run(void)
{
size_t n;
demux_res_t demux_res;
stream_t input_stream;
uint32_t samplesdone;
uint32_t elapsedtime = 0;
int samplesdecoded;
unsigned int i;
unsigned char* buffer;
alac_file alac;
intptr_t param;
/* Clean and initialize decoder structures */
memset(&demux_res , 0, sizeof(demux_res));
if (codec_init()) {
LOGF("ALAC: Error initialising codec\n");
return CODEC_ERROR;
}
ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
codec_set_replaygain(ci->id3);
ci->seek_buffer(0);
stream_create(&input_stream,ci);
/* Read from ci->id3->offset before calling qtmovie_read. */
samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /
(ci->id3->bitrate*128));
/* if qtmovie_read returns successfully, the stream is up to
* the movie data, which can be used directly by the decoder */
if (!qtmovie_read(&input_stream, &demux_res)) {
LOGF("ALAC: Error initialising file\n");
return CODEC_ERROR;
}
/* initialise the sound converter */
create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
alac_set_info(&alac, demux_res.codecdata);
/* Set i for first frame, seek to desired sample position for resuming. */
i=0;
if (samplesdone > 0) {
if (m4a_seek(&demux_res, &input_stream, samplesdone,
&samplesdone, (int*) &i)) {
elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
ci->set_elapsed(elapsedtime);
} else {
samplesdone = 0;
}
}
/* The main decoding loop */
while (i < demux_res.num_sample_byte_sizes) {
enum codec_command_action action = ci->get_command(¶m);
if (action == CODEC_ACTION_HALT)
break;
/* Request the required number of bytes from the input buffer */
buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
/* Deal with any pending seek requests */
if (action == CODEC_ACTION_SEEK_TIME) {
if (m4a_seek(&demux_res, &input_stream,
(param/10) * (ci->id3->frequency/100),
&samplesdone, (int *)&i)) {
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
}
ci->set_elapsed(elapsedtime);
ci->seek_complete();
}
/* Request the required number of bytes from the input buffer */
buffer=ci->request_buffer(&n, ALAC_BYTE_BUFFER_SIZE);
/* Decode one block - returned samples will be host-endian */
samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
ci->yield();
/* Advance codec buffer by amount of consumed bytes */
ci->advance_buffer(alac.bytes_consumed);
/* Output the audio */
ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
/* Update the elapsed-time indicator */
samplesdone+=samplesdecoded;
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
ci->set_elapsed(elapsedtime);
i++;
}
LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone);
return CODEC_OK;
}
/* this is the codec entry point */
enum codec_status codec_main(void)
{
size_t n;
demux_res_t demux_res;
stream_t input_stream;
uint32_t samplesdone;
uint32_t elapsedtime;
uint32_t sample_duration;
uint32_t sample_byte_size;
int samplesdecoded;
unsigned int i;
unsigned char* buffer;
alac_file alac;
int retval;
/* Generic codec initialisation */
ci->configure(DSP_SET_STEREO_MODE, STEREO_NONINTERLEAVED);
ci->configure(DSP_SET_SAMPLE_DEPTH, ALAC_OUTPUT_DEPTH-1);
next_track:
if (codec_init()) {
LOGF("ALAC: Error initialising codec\n");
retval = CODEC_ERROR;
goto exit;
}
while (!*ci->taginfo_ready && !ci->stop_codec)
ci->sleep(1);
ci->configure(DSP_SWITCH_FREQUENCY, ci->id3->frequency);
codec_set_replaygain(ci->id3);
stream_create(&input_stream,ci);
/* Read from ci->id3->offset before calling qtmovie_read. */
samplesdone = (uint32_t)(((uint64_t)(ci->id3->offset) * ci->id3->frequency) /
(ci->id3->bitrate*128));
/* if qtmovie_read returns successfully, the stream is up to
* the movie data, which can be used directly by the decoder */
if (!qtmovie_read(&input_stream, &demux_res)) {
LOGF("ALAC: Error initialising file\n");
retval = CODEC_ERROR;
goto done;
}
/* initialise the sound converter */
create_alac(demux_res.sound_sample_size, demux_res.num_channels,&alac);
alac_set_info(&alac, demux_res.codecdata);
/* Set i for first frame, seek to desired sample position for resuming. */
i=0;
if (samplesdone > 0) {
if (alac_seek(&demux_res, &input_stream, samplesdone,
&samplesdone, (int*) &i)) {
elapsedtime = (samplesdone * 10) / (ci->id3->frequency / 100);
ci->set_elapsed(elapsedtime);
} else {
samplesdone = 0;
}
}
/* The main decoding loop */
while (i < demux_res.num_sample_byte_sizes) {
ci->yield();
if (ci->stop_codec || ci->new_track) {
break;
}
/* Deal with any pending seek requests */
if (ci->seek_time) {
if (alac_seek(&demux_res, &input_stream,
((ci->seek_time-1)/10) * (ci->id3->frequency/100),
&samplesdone, (int *)&i)) {
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
ci->set_elapsed(elapsedtime);
}
ci->seek_complete();
}
/* Lookup the length (in samples and bytes) of block i */
if (!get_sample_info(&demux_res, i, &sample_duration,
&sample_byte_size)) {
LOGF("ALAC: Error in get_sample_info\n");
retval = CODEC_ERROR;
goto done;
}
/* Request the required number of bytes from the input buffer */
buffer=ci->request_buffer(&n,sample_byte_size);
if (n!=sample_byte_size) {
retval = CODEC_ERROR;
goto done;
}
/* Decode one block - returned samples will be host-endian */
ci->yield();
samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, ci->yield);
/* Advance codec buffer n bytes */
ci->advance_buffer(n);
/* Output the audio */
ci->yield();
ci->pcmbuf_insert(outputbuffer[0], outputbuffer[1], samplesdecoded);
/* Update the elapsed-time indicator */
samplesdone+=sample_duration;
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
ci->set_elapsed(elapsedtime);
i++;
}
retval = CODEC_OK;
done:
LOGF("ALAC: Decoded %ld samples\n",samplesdone);
if (ci->request_next_track())
goto next_track;
exit:
return retval;
}