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rockbox/apps/codecs/alac.c

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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 Dave Chapman
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "codeclib.h"
#include <codecs/libalac/demux.h>
#include <codecs/libalac/decomp.h>
#include <codecs/libalac/stream.h>
#ifndef SIMULATOR
extern char iramcopy[];
extern char iramstart[];
extern char iramend[];
#endif
#define destBufferSize (1024*16)
char inputBuffer[1024*32]; /* Input buffer */
int32_t outputbuffer[ALAC_MAX_CHANNELS][ALAC_BLOCKSIZE] IBSS_ATTR;
size_t mdat_offset;
struct codec_api* rb;
struct codec_api* ci;
/* Implementation of the stream.h functions used by libalac */
#define _Swap32(v) do { \
v = (((v) & 0x000000FF) << 0x18) | \
(((v) & 0x0000FF00) << 0x08) | \
(((v) & 0x00FF0000) >> 0x08) | \
(((v) & 0xFF000000) >> 0x18); } while(0)
#define _Swap16(v) do { \
v = (((v) & 0x00FF) << 0x08) | \
(((v) & 0xFF00) >> 0x08); } while (0)
/* A normal read without any byte-swapping */
void stream_read(stream_t *stream, size_t size, void *buf)
{
ci->read_filebuf(buf,size);
if (ci->curpos >= ci->filesize) { stream->eof=1; }
}
int32_t stream_read_int32(stream_t *stream)
{
int32_t v;
stream_read(stream, 4, &v);
#ifdef ROCKBOX_LITTLE_ENDIAN
_Swap32(v);
#endif
return v;
}
uint32_t stream_read_uint32(stream_t *stream)
{
uint32_t v;
stream_read(stream, 4, &v);
#ifdef ROCKBOX_LITTLE_ENDIAN
_Swap32(v);
#endif
return v;
}
int16_t stream_read_int16(stream_t *stream)
{
int16_t v;
stream_read(stream, 2, &v);
#ifdef ROCKBOX_LITTLE_ENDIAN
_Swap16(v);
#endif
return v;
}
uint16_t stream_read_uint16(stream_t *stream)
{
uint16_t v;
stream_read(stream, 2, &v);
#ifdef ROCKBOX_LITTLE_ENDIAN
_Swap16(v);
#endif
return v;
}
int8_t stream_read_int8(stream_t *stream)
{
int8_t v;
stream_read(stream, 1, &v);
return v;
}
uint8_t stream_read_uint8(stream_t *stream)
{
uint8_t v;
stream_read(stream, 1, &v);
return v;
}
void stream_skip(stream_t *stream, size_t skip)
{
(void)stream;
ci->advance_buffer(skip);
}
int stream_eof(stream_t *stream)
{
return stream->eof;
}
void stream_create(stream_t *stream)
{
stream->eof=0;
}
/* This function was part of the original alac decoder implementation */
static int get_sample_info(demux_res_t *demux_res, uint32_t samplenum,
uint32_t *sample_duration,
uint32_t *sample_byte_size)
{
unsigned int duration_index_accum = 0;
unsigned int duration_cur_index = 0;
if (samplenum >= demux_res->num_sample_byte_sizes) {
return 0;
}
if (!demux_res->num_time_to_samples) {
return 0;
}
while ((demux_res->time_to_sample[duration_cur_index].sample_count
+ duration_index_accum) <= samplenum) {
duration_index_accum +=
demux_res->time_to_sample[duration_cur_index].sample_count;
duration_cur_index++;
if (duration_cur_index >= demux_res->num_time_to_samples) {
return 0;
}
}
*sample_duration =
demux_res->time_to_sample[duration_cur_index].sample_duration;
*sample_byte_size = demux_res->sample_byte_size[samplenum];
return 1;
}
/* Seek to sample_loc (or close to it). Return 1 on success (and
modify samplesdone and currentblock), 0 if failed
Seeking uses the following two arrays:
1) the sample_byte_size array contains the length in bytes of
each block ("sample" in Applespeak).
2) the time_to_sample array contains the duration (in samples) of
each block of data.
So we just find the block number we are going to seek to (using
time_to_sample) and then find the offset in the file (using
sample_byte_size).
Each ALAC block seems to be independent of all the others.
*/
static unsigned int alac_seek (demux_res_t* demux_res,
unsigned int sample_loc,
uint32_t* samplesdone, int* currentblock)
{
int flag;
unsigned int i,j;
unsigned int newblock;
unsigned int newsample;
unsigned int newpos;
/* First check we have the appropriate metadata - we should always
have it. */
if ((demux_res->num_time_to_samples==0) ||
(demux_res->num_sample_byte_sizes==0)) { return 0; }
/* Find the destination block from time_to_sample array */
i=0;
newblock=0;
newsample=0;
flag=0;
while ((i<demux_res->num_time_to_samples) && (flag==0) &&
(newsample < sample_loc)) {
j=(sample_loc-newsample) /
demux_res->time_to_sample[i].sample_duration;
if (j <= demux_res->time_to_sample[i].sample_count) {
newblock+=j;
newsample+=j*demux_res->time_to_sample[i].sample_duration;
flag=1;
} else {
newsample+=(demux_res->time_to_sample[i].sample_duration
* demux_res->time_to_sample[i].sample_count);
newblock+=demux_res->time_to_sample[i].sample_count;
i++;
}
}
/* We know the new block, now calculate the file position */
newpos=mdat_offset;
for (i=0;i<newblock;i++) {
newpos+=demux_res->sample_byte_size[i];
}
/* We know the new file position, so let's try to seek to it */
if (ci->seek_buffer(newpos)) {
*samplesdone=newsample;
*currentblock=newblock;
return 1;
} else {
return 0;
}
}
/* this is the codec entry point */
enum codec_status codec_start(struct codec_api* api)
{
size_t n;
demux_res_t demux_res;
static 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;
/* Generic codec initialisation */
TEST_CODEC_API(api);
rb = api;
ci = (struct codec_api*)api;
#ifndef SIMULATOR
rb->memcpy(iramstart, iramcopy, iramend-iramstart);
#endif
ci->configure(CODEC_SET_FILEBUF_LIMIT, (int *)(1024*1024*10));
ci->configure(CODEC_SET_FILEBUF_WATERMARK, (int *)(1024*512));
ci->configure(CODEC_SET_FILEBUF_CHUNKSIZE, (int *)(1024*128));
ci->configure(CODEC_DSP_ENABLE, (bool *)true);
ci->configure(DSP_DITHER, (bool *)false);
ci->configure(DSP_SET_STEREO_MODE, (int *)STEREO_NONINTERLEAVED);
ci->configure(DSP_SET_SAMPLE_DEPTH, (int *)(28));
next_track:
if (codec_init(api)) {
LOGF("ALAC: Error initialising codec\n");
return CODEC_ERROR;
}
while (!rb->taginfo_ready)
rb->yield();
ci->configure(DSP_SET_FREQUENCY, (long *)(rb->id3->frequency));
stream_create(&input_stream);
/* 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;
}
/* Keep track of start of stream in file - used for seeking */
mdat_offset=ci->curpos;
/* initialise the sound converter */
create_alac(demux_res.sample_size, demux_res.num_channels,&alac);
alac_set_info(&alac, demux_res.codecdata);
i=0;
samplesdone=0;
/* The main decoding loop */
while (i < demux_res.num_sample_byte_sizes) {
rb->yield();
if (ci->stop_codec || ci->reload_codec) {
break;
}
/* Deal with any pending seek requests */
if (ci->seek_time) {
if (alac_seek(&demux_res,
(ci->seek_time/10) * (ci->id3->frequency/100),
&samplesdone, &i)) {
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
ci->set_elapsed(elapsedtime);
}
ci->seek_time = 0;
}
/* 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");
return CODEC_ERROR;
}
/* Request the required number of bytes from the input buffer */
buffer=ci->request_buffer((long*)&n,sample_byte_size);
if (n!=sample_byte_size) {
/* The decode_frame function requires the whole frame, so if we
can't get it contiguously from the buffer, then we need to
copy it via a read - i.e. we are at the buffer wraparound
point */
/* Check we estimated the maximum buffer size correctly */
if (sample_byte_size > sizeof(inputBuffer)) {
LOGF("ALAC: Input buffer < %d bytes\n",sample_byte_size);
return CODEC_ERROR;
}
n=ci->read_filebuf(inputBuffer,sample_byte_size);
if (n!=sample_byte_size) {
LOGF("ALAC: Error reading data\n");
return CODEC_ERROR;
}
buffer=inputBuffer;
}
/* Decode one block - returned samples will be host-endian */
rb->yield();
samplesdecoded=alac_decode_frame(&alac, buffer, outputbuffer, rb->yield);
/* Advance codec buffer - unless we did a read */
if ((char*)buffer!=(char*)inputBuffer) {
ci->advance_buffer(n);
}
/* Output the audio */
rb->yield();
while(!ci->pcmbuf_insert_split(outputbuffer[0],
outputbuffer[1],
samplesdecoded*sizeof(int32_t)))
rb->yield();
/* Update the elapsed-time indicator */
samplesdone+=sample_duration;
elapsedtime=(samplesdone*10)/(ci->id3->frequency/100);
ci->set_elapsed(elapsedtime);
/* Keep track of current position - for resuming */
ci->set_offset(elapsedtime);
i++;
}
LOGF("ALAC: Decoded %d samples\n",samplesdone);
if (ci->request_next_track())
goto next_track;
return CODEC_OK;
}
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