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rockbox/apps/codecs/libmusepack/mpc_demux.c
Andree Buschmann d7ee0fe076 Housekeeping. Comment musepack code seqments unused in rockbox. 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27111 a1c6a512-1295-4272-9138-f99709370657
2010-06-24 18:48:04 +00:00

672 lines
23 KiB
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/*
Copyright (c) 2005-2009, The Musepack Development Team
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided
with the distribution.
* Neither the name of the The Musepack Development Team nor the
names of its contributors may be used to endorse or promote
products derived from this software without specific prior
written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <math.h>
#include <string.h>
#include "streaminfo.h"
#include "mpcdec.h"
#include "internal.h"
#include "decoder.h"
#include "huffman.h"
#include "mpc_bits_reader.h"
#include <codeclib.h>
/// maximum number of seek points in the table. The distance between points will
/// be adapted so this value is never exceeded.
#define MAX_SEEK_TABLE_SIZE 8192
// globals
static mpc_uint8_t g_buffer[DEMUX_BUFFER_SIZE + MAX_FRAME_SIZE];
static mpc_seek_t g_seek_table[MAX_SEEK_TABLE_SIZE];
static mpc_demux g_mpc_demux IBSS_ATTR;
enum {
MPC_BUFFER_SWAP = 1,
MPC_BUFFER_FULL = 2,
};
static void mpc_demux_clear_buff(mpc_demux * d)
{
d->bytes_total = 0;
d->bits_reader.buff = d->buffer;
d->bits_reader.count = 8;
d->bits_reader.buffered_addr = 0;
d->bits_reader.buffered_code = 0;
d->block_bits = 0;
d->block_frames = 0;
memset(d->buffer, 0, sizeof(g_buffer));
}
static mpc_uint32_t
mpc_demux_fill(mpc_demux * d, mpc_uint32_t min_bytes, int flags)
{
mpc_uint32_t unread_bytes = d->bytes_total + d->buffer - d->bits_reader.buff
- ((8 - d->bits_reader.count) >> 3);
int offset = 0;
if (min_bytes == 0 || min_bytes > DEMUX_BUFFER_SIZE ||
(unread_bytes < min_bytes && flags & MPC_BUFFER_FULL))
min_bytes = DEMUX_BUFFER_SIZE;
if (unread_bytes < min_bytes) {
mpc_uint32_t bytes2read = min_bytes - unread_bytes;
mpc_uint32_t bytes_free = DEMUX_BUFFER_SIZE - d->bytes_total;
if (flags & MPC_BUFFER_SWAP) {
bytes2read &= -1 << 2;
offset = (unread_bytes + 3) & ( -1 << 2);
offset -= unread_bytes;
}
if (bytes2read > bytes_free) {
if (d->bits_reader.count == 0) {
d->bits_reader.count = 8;
d->bits_reader.buff++;
}
memmove(d->buffer + offset, d->bits_reader.buff, unread_bytes);
d->bits_reader.buff = d->buffer + offset;
d->bytes_total = unread_bytes + offset;
}
bytes2read = d->r->read(d->r, d->buffer + d->bytes_total, bytes2read);
if (flags & MPC_BUFFER_SWAP){
unsigned int i, * tmp = (unsigned int *) (d->buffer + d->bytes_total);
for(i = 0 ;i < (bytes2read >> 2); i++)
tmp[i] = swap32(tmp[i]);
}
d->bytes_total += bytes2read;
return bytes2read;
}
return (mpc_uint32_t) -1;
}
/**
* seek to a bit position in the stream
* @param d demuxer context
* @param fpos position in the stream in bits from the beginning of mpc datas
* @param min_bytes number of bytes to load after seeking
*/
static void
mpc_demux_seek(mpc_demux * d, mpc_seek_t fpos, mpc_uint32_t min_bytes) {
// d->bits_reader.buff - d->buffer = current byte position within buffer
// d->bytes_total = buffer is filled with bytes_total bytes
// fpos = desired file position in bit (not byte)
// buf_fpos = desired byte position within buffer
mpc_seek_t next_pos = fpos>>3;
mpc_int_t buf_fpos = next_pos - d->r->tell(d->r) + d->bytes_total;
// is desired byte position within lower and upper boundaries of buffer?
if (buf_fpos >= 0 && buf_fpos + min_bytes <= d->bytes_total) {
// desired bytes are available in current buffer
d->bits_reader.buff += buf_fpos - (d->bits_reader.buff - d->buffer);
d->bits_reader.count = 8 - (fpos & 7);
} else {
// buffer needs to be refilled
if (d->si.stream_version == 7)
next_pos = ((next_pos - d->si.header_position) & (-1 << 2)) + d->si.header_position;
buf_fpos = fpos - (next_pos << 3);
d->r->seek(d->r, (mpc_int32_t) next_pos);
mpc_demux_clear_buff(d);
if (d->si.stream_version == 7)
mpc_demux_fill(d, DEMUX_BUFFER_SIZE, MPC_BUFFER_SWAP);
else
mpc_demux_fill(d, DEMUX_BUFFER_SIZE, 0);
d->bits_reader.buff += buf_fpos >> 3;
d->bits_reader.count = 8 - (buf_fpos & 7);
}
}
/**
* return the current position in the stream (in bits) from the beginning
* of the file
* @param d demuxer context
* @return current stream position in bits
*/
static mpc_seek_t mpc_demux_pos(mpc_demux * d)
{
return (((mpc_seek_t)(d->r->tell(d->r)) - d->bytes_total +
d->bits_reader.buff - d->buffer) << 3) + 8 - d->bits_reader.count;
}
/**
* Searches for a ID3v2-tag and reads the length (in bytes) of it.
*
* @param d demuxer context
* @return size of tag, in bytes
* @return MPC_STATUS_FILE on errors of any kind
*/
static mpc_int32_t mpc_demux_skip_id3v2(mpc_demux * d)
{
mpc_uint8_t tmp [4];
mpc_bool_t footerPresent; // ID3v2.4-flag
mpc_int32_t size;
// we must be at the beginning of the stream
mpc_demux_fill(d, 3, 0);
// check id3-tag
if ( 0 != memcmp( d->bits_reader.buff, "ID3", 3 ) )
return 0;
mpc_demux_fill(d, 10, 0);
mpc_bits_read(&d->bits_reader, 24); // read ID3
mpc_bits_read(&d->bits_reader, 16); // read tag version
tmp[0] = mpc_bits_read(&d->bits_reader, 8); // read flags
footerPresent = tmp[0] & 0x10;
if ( tmp[0] & 0x0F )
return MPC_STATUS_FILE; // not (yet???) allowed
tmp[0] = mpc_bits_read(&d->bits_reader, 8); // read size
tmp[1] = mpc_bits_read(&d->bits_reader, 8); // read size
tmp[2] = mpc_bits_read(&d->bits_reader, 8); // read size
tmp[3] = mpc_bits_read(&d->bits_reader, 8); // read size
if ( (tmp[0] | tmp[1] | tmp[2] | tmp[3]) & 0x80 )
return MPC_STATUS_FILE; // not allowed
// read headerSize (syncsave: 4 * $0xxxxxxx = 28 significant bits)
size = tmp[0] << 21;
size |= tmp[1] << 14;
size |= tmp[2] << 7;
size |= tmp[3];
size += 10; //header
if ( footerPresent ) size += 10;
// This is called before file headers get read, streamversion etc isn't yet known, demuxing isn't properly initialized and we can't call mpc_demux_seek() from here.
mpc_demux_clear_buff(d);
if (!d->r->seek(d->r, size)) return MPC_STATUS_FILE;
return size;
}
static mpc_status mpc_demux_seek_init(mpc_demux * d)
{
size_t seek_table_size;
if (d->seek_table != 0)
return MPC_STATUS_OK;
d->seek_pwr = 6;
if (d->si.block_pwr > d->seek_pwr)
d->seek_pwr = d->si.block_pwr;
seek_table_size = (2 + d->si.samples / (MPC_FRAME_LENGTH << d->seek_pwr));
while (seek_table_size > MAX_SEEK_TABLE_SIZE) {
d->seek_pwr++;
seek_table_size = (2 + d->si.samples / (MPC_FRAME_LENGTH << d->seek_pwr));
}
d->seek_table = g_seek_table;
if (d->seek_table == 0)
return MPC_STATUS_FILE;
d->seek_table[0] = (mpc_seek_t)mpc_demux_pos(d);
d->seek_table_size = 1;
return MPC_STATUS_OK;
}
static void mpc_demux_ST(mpc_demux * d)
{
mpc_uint64_t tmp;
mpc_seek_t * table, last[2];
mpc_bits_reader r = d->bits_reader;
mpc_uint_t i, diff_pwr = 0, mask;
mpc_uint32_t file_table_size;
if (d->seek_table != 0)
return;
mpc_bits_get_size(&r, &tmp);
file_table_size = (mpc_seek_t) tmp;
d->seek_pwr = d->si.block_pwr + mpc_bits_read(&r, 4);
tmp = 2 + d->si.samples / (MPC_FRAME_LENGTH << d->seek_pwr);
while (tmp > MAX_SEEK_TABLE_SIZE) {
d->seek_pwr++;
diff_pwr++;
tmp = 2 + d->si.samples / (MPC_FRAME_LENGTH << d->seek_pwr);
}
if ((file_table_size >> diff_pwr) > tmp)
file_table_size = tmp << diff_pwr;
d->seek_table = g_seek_table;
d->seek_table_size = (file_table_size + ((1 << diff_pwr) - 1)) >> diff_pwr;
table = d->seek_table;
mpc_bits_get_size(&r, &tmp);
table[0] = last[0] = (mpc_seek_t) (tmp + d->si.header_position) * 8;
if (d->seek_table_size == 1)
return;
mpc_bits_get_size(&r, &tmp);
last[1] = (mpc_seek_t) (tmp + d->si.header_position) * 8;
if (diff_pwr == 0) table[1] = last[1];
mask = (1 << diff_pwr) - 1;
for (i = 2; i < file_table_size; i++) {
int code = mpc_bits_golomb_dec(&r, 12);
if (code & 1)
code = -(code & (-1 << 1));
code <<= 2;
last[i & 1] = code + 2 * last[(i-1) & 1] - last[i & 1];
if ((i & mask) == 0)
table[i >> diff_pwr] = last[i & 1];
}
}
static void mpc_demux_SP(mpc_demux * d, int size, int block_size)
{
mpc_seek_t cur;
mpc_uint64_t ptr;
mpc_block b;
int st_head_size;
cur = mpc_demux_pos(d);
mpc_bits_get_size(&d->bits_reader, &ptr);
mpc_demux_seek(d, (ptr - size) * 8 + cur, 11);
st_head_size = mpc_bits_get_block(&d->bits_reader, &b);
if (memcmp(b.key, "ST", 2) == 0) {
/* rockbox: not used
d->chap_pos = (ptr - size + b.size + st_head_size) * 8 + cur;
d->chap_nb = -1;
*/
mpc_demux_fill(d, (mpc_uint32_t) b.size, 0);
mpc_demux_ST(d);
}
mpc_demux_seek(d, cur, 11 + block_size);
}
/* rockbox: not used
static void mpc_demux_chap_find(mpc_demux * d)
{
mpc_block b;
int tag_size = 0, chap_size = 0, size, i = 0;
d->chap_nb = 0;
if (d->si.stream_version < 8)
return;
if (d->chap_pos == 0) {
mpc_uint64_t cur_pos = (d->si.header_position + 4) * 8;
mpc_demux_seek(d, cur_pos, 11); // seek to the beginning of the stream
size = mpc_bits_get_block(&d->bits_reader, &b);
while (memcmp(b.key, "SE", 2) != 0) {
if (mpc_check_key(b.key) != MPC_STATUS_OK)
return;
if (memcmp(b.key, "CT", 2) == 0) {
if (d->chap_pos == 0) d->chap_pos = cur_pos;
} else
d->chap_pos = 0;
cur_pos += (size + b.size) * 8;
mpc_demux_seek(d, cur_pos, 11);
size = mpc_bits_get_block(&d->bits_reader, &b);
}
if (d->chap_pos == 0)
d->chap_pos = cur_pos;
}
mpc_demux_seek(d, d->chap_pos, 20);
size = mpc_bits_get_block(&d->bits_reader, &b);
while (memcmp(b.key, "CT", 2) == 0) {
mpc_uint64_t chap_sample;
d->chap_nb++;
chap_size += size;
size = mpc_bits_get_size(&d->bits_reader, &chap_sample) + 4;
chap_size += size;
tag_size += b.size - size;
mpc_demux_seek(d, d->chap_pos + (chap_size + tag_size) * 8, 20);
size = mpc_bits_get_block(&d->bits_reader, &b);
}
if (d->chap_nb > 0) {
char * ptag;
d->chap = malloc(sizeof(mpc_chap_info) * d->chap_nb + tag_size);
ptag = (char*)(d->chap + d->chap_nb);
mpc_demux_seek(d, d->chap_pos, 11);
size = mpc_bits_get_block(&d->bits_reader, &b);
while (memcmp(b.key, "CT", 2) == 0) {
mpc_demux_fill(d, 11 + (mpc_uint32_t) b.size, 0);
size = mpc_bits_get_size(&d->bits_reader, &d->chap[i].sample) + 4;
d->chap[i].gain = (mpc_uint16_t) mpc_bits_read(&d->bits_reader, 16);
d->chap[i].peak = (mpc_uint16_t) mpc_bits_read(&d->bits_reader, 16);
memcpy(ptag, d->bits_reader.buff + ((8 - d->bits_reader.count) >> 3), b.size - size);
d->bits_reader.buff += b.size - size;
d->chap[i].tag_size = b.size - size;
d->chap[i].tag = ptag;
ptag += b.size - size;
i++;
size = mpc_bits_get_block(&d->bits_reader, &b);
}
}
d->bits_reader.buff -= size;
}
*/
/**
* Gets the number of chapters in the stream
* @param d pointer to a musepack demuxer
* @return the number of chapters found in the stream
*/
/* rockbox: not used
mpc_int_t mpc_demux_chap_nb(mpc_demux * d)
{
if (d->chap_nb == -1)
mpc_demux_chap_find(d);
return d->chap_nb;
}
*/
/**
* Gets datas associated to a given chapter
* The chapter tag is an APEv2 tag without the preamble
* @param d pointer to a musepack demuxer
* @param chap_nb chapter number you want datas (from 0 to mpc_demux_chap_nb(d) - 1)
* @return the chapter information structure
*/
/* rockbox: not used
mpc_chap_info const * mpc_demux_chap(mpc_demux * d, int chap_nb)
{
if (d->chap_nb == -1)
mpc_demux_chap_find(d);
if (chap_nb >= d->chap_nb || chap_nb < 0)
return 0;
return &d->chap[chap_nb];
}
*/
static mpc_status mpc_demux_header(mpc_demux * d)
{
char magic[4];
d->si.pns = 0xFF;
/* rockbox: not used
d->si.profile_name = "n.a.";
*/
// get header position
d->si.header_position = mpc_demux_skip_id3v2(d);
if(d->si.header_position < 0) return MPC_STATUS_FILE;
d->si.tag_offset = d->si.total_file_length = d->r->get_size(d->r);
mpc_demux_fill(d, 4, 0);
magic[0] = mpc_bits_read(&d->bits_reader, 8);
magic[1] = mpc_bits_read(&d->bits_reader, 8);
magic[2] = mpc_bits_read(&d->bits_reader, 8);
magic[3] = mpc_bits_read(&d->bits_reader, 8);
if (memcmp(magic, "MP+", 3) == 0) {
d->si.stream_version = magic[3] & 15;
d->si.pns = magic[3] >> 4;
if (d->si.stream_version == 7) {
mpc_status ret;
mpc_demux_fill(d, 6 * 4, MPC_BUFFER_SWAP); // header block size + endian convertion
ret = streaminfo_read_header_sv7(&d->si, &d->bits_reader);
if (ret != MPC_STATUS_OK) return ret;
} else {
return MPC_STATUS_INVALIDSV;
}
} else if (memcmp(magic, "MPCK", 4) == 0) {
mpc_block b;
int size;
mpc_demux_fill(d, 11, 0); // max header block size
size = mpc_bits_get_block(&d->bits_reader, &b);
while( memcmp(b.key, "AP", 2) != 0 ){ // scan all blocks until audio
if (mpc_check_key(b.key) != MPC_STATUS_OK)
return MPC_STATUS_INVALIDSV;
if (b.size > (mpc_uint64_t) DEMUX_BUFFER_SIZE - 11)
return MPC_STATUS_INVALIDSV;
mpc_demux_fill(d, 11 + (mpc_uint32_t) b.size, 0);
if (memcmp(b.key, "SH", 2) == 0){
int ret = streaminfo_read_header_sv8(&d->si, &d->bits_reader, (mpc_uint32_t) b.size);
if (ret != MPC_STATUS_OK) return ret;
} else if (memcmp(b.key, "RG", 2) == 0)
streaminfo_gain(&d->si, &d->bits_reader);
else if (memcmp(b.key, "EI", 2) == 0)
streaminfo_encoder_info(&d->si, &d->bits_reader);
else if (memcmp(b.key, "SO", 2) == 0)
mpc_demux_SP(d, size, (mpc_uint32_t) b.size);
else if (memcmp(b.key, "ST", 2) == 0)
mpc_demux_ST(d);
d->bits_reader.buff += b.size;
size = mpc_bits_get_block(&d->bits_reader, &b);
}
d->bits_reader.buff -= size;
if (d->si.stream_version == 0) // si not initialized !!!
return MPC_STATUS_INVALIDSV;
} else
return MPC_STATUS_INVALIDSV;
return MPC_STATUS_OK;
}
mpc_demux * mpc_demux_init(mpc_reader * p_reader)
{
mpc_demux* p_tmp = &g_mpc_demux;
if (p_tmp != 0) {
memset(p_tmp, 0, sizeof(mpc_demux));
p_tmp->buffer = g_buffer;
p_tmp->r = p_reader;
/* rockbox: not used
p_tmp->chap_nb = -1;
*/
mpc_demux_clear_buff(p_tmp);
if (mpc_demux_header(p_tmp) == MPC_STATUS_OK &&
mpc_demux_seek_init(p_tmp) == MPC_STATUS_OK) {
p_tmp->d = mpc_decoder_init(&p_tmp->si);
} else {
if (p_tmp->seek_table)
memset(p_tmp->seek_table, 0, sizeof(g_seek_table));
p_tmp = 0;
}
}
return p_tmp;
}
/* rockbox: not used
void mpc_demux_exit(mpc_demux * d)
{
mpc_decoder_exit(d->d);
memset(d->seek_table, 0, sizeof(g_seek_table));
}
*/
void mpc_demux_get_info(mpc_demux * d, mpc_streaminfo * i)
{
memcpy(i, &d->si, sizeof d->si);
}
mpc_status mpc_demux_decode(mpc_demux * d, mpc_frame_info * i)
{
mpc_bits_reader r;
if (d->si.stream_version >= 8) {
i->is_key_frame = MPC_FALSE;
if (d->block_frames == 0) {
mpc_block b = {{0,0},0};
d->bits_reader.count &= -8;
if (d->d->decoded_samples == (d->seek_table_size << d->seek_pwr) * MPC_FRAME_LENGTH) {
d->seek_table[d->seek_table_size] = (mpc_seek_t) mpc_demux_pos(d);
d->seek_table_size ++;
}
mpc_demux_fill(d, 11, 0); // max header block size
mpc_bits_get_block(&d->bits_reader, &b);
while( memcmp(b.key, "AP", 2) != 0 ) { // scan all blocks until audio
if (mpc_check_key(b.key) != MPC_STATUS_OK)
goto error;
if (memcmp(b.key, "SE", 2) == 0) { // end block
i->bits = -1;
return MPC_STATUS_OK;
}
if (mpc_demux_fill(d, 11 + (mpc_uint32_t) b.size, 0) == 0)
goto error;
d->bits_reader.buff += b.size;
mpc_bits_get_block(&d->bits_reader, &b);
}
d->block_bits = (mpc_uint32_t) b.size * 8;
d->block_frames = 1 << d->si.block_pwr;
i->is_key_frame = MPC_TRUE;
}
if (d->buffer + d->bytes_total - d->bits_reader.buff <= MAX_FRAME_SIZE)
mpc_demux_fill(d, (d->block_bits >> 3) + 1, 0);
r = d->bits_reader;
mpc_decoder_decode_frame(d->d, &d->bits_reader, i);
d->block_bits -= ((d->bits_reader.buff - r.buff) << 3) + r.count - d->bits_reader.count;
d->block_frames--;
if (d->block_bits < 0 || (d->block_frames == 0 && d->block_bits > 7))
goto error;
} else {
if (d->d->decoded_samples == (d->seek_table_size << d->seek_pwr) * MPC_FRAME_LENGTH) {
d->seek_table[d->seek_table_size] = (mpc_seek_t) mpc_demux_pos(d);
d->seek_table_size ++;
}
mpc_demux_fill(d, MAX_FRAME_SIZE, MPC_BUFFER_FULL | MPC_BUFFER_SWAP);
d->block_bits = (mpc_int_t) mpc_bits_read(&d->bits_reader, 20); // read frame size
if (MPC_FRAME_LENGTH > d->d->samples - d->d->decoded_samples - 1) d->block_bits += 11; // we will read last frame size
r = d->bits_reader;
mpc_decoder_decode_frame(d->d, &d->bits_reader, i);
if (i->bits != -1 && d->block_bits != (mpc_int32_t)(((d->bits_reader.buff - r.buff) << 3) + r.count - d->bits_reader.count))
goto error;
}
if (i->bits != -1 && d->buffer + d->bytes_total < d->bits_reader.buff + ((8 - d->bits_reader.count) >> 3))
goto error;
return MPC_STATUS_OK;
error:
i->bits = -1; // we pretend it's end of file
return MPC_STATUS_INVALIDSV;
}
/* rockbox: not used
mpc_status mpc_demux_seek_second(mpc_demux * d, double seconds)
{
return mpc_demux_seek_sample(d, (mpc_int64_t)(seconds * (double)d->si.sample_freq + 0.5));
}
*/
mpc_status mpc_demux_seek_sample(mpc_demux * d, mpc_uint64_t destsample)
{
mpc_uint32_t fwd, samples_to_skip, i;
mpc_uint32_t block_samples = MPC_FRAME_LENGTH << d->si.block_pwr;
mpc_seek_t fpos;
destsample += d->si.beg_silence;
if (destsample > d->si.samples) destsample = d->si.samples;
fwd = (mpc_uint32_t) (destsample / block_samples);
samples_to_skip = MPC_DECODER_SYNTH_DELAY +
(mpc_uint32_t) (destsample % block_samples);
if (d->si.stream_version == 7) {
if (fwd > 32) {
fwd -= 32;
samples_to_skip += MPC_FRAME_LENGTH * 32;
} else {
samples_to_skip += MPC_FRAME_LENGTH * fwd;
fwd = 0;
}
}
i = fwd >> (d->seek_pwr - d->si.block_pwr);
if (i >= d->seek_table_size)
i = d->seek_table_size - 1;
fpos = d->seek_table[i];
i <<= d->seek_pwr - d->si.block_pwr;
d->d->decoded_samples = i * block_samples;
if (d->si.stream_version >= 8) {
mpc_block b;
int size;
mpc_demux_seek(d, fpos, 11);
size = mpc_bits_get_block(&d->bits_reader, &b);
while(i < fwd) {
if (memcmp(b.key, "AP", 2) == 0) {
if (d->d->decoded_samples == (d->seek_table_size << d->seek_pwr) * MPC_FRAME_LENGTH) {
d->seek_table[d->seek_table_size] = (mpc_seek_t) mpc_demux_pos(d) - 8 * size;
d->seek_table_size ++;
}
d->d->decoded_samples += block_samples;
i++;
}
fpos += ((mpc_uint32_t)b.size + size) * 8;
mpc_demux_seek(d, fpos, 11);
size = mpc_bits_get_block(&d->bits_reader, &b);
}
d->bits_reader.buff -= size;
} else {
mpc_decoder_reset_scf(d->d, fwd != 0);
mpc_demux_seek(d, fpos, 4);
for( ; i < fwd; i++){
if (d->d->decoded_samples == (d->seek_table_size << d->seek_pwr) * MPC_FRAME_LENGTH) {
d->seek_table[d->seek_table_size] = (mpc_seek_t) mpc_demux_pos(d);
d->seek_table_size ++;
}
d->d->decoded_samples += block_samples;
fpos += mpc_bits_read(&d->bits_reader, 20) + 20;
mpc_demux_seek(d, fpos, 4);
}
}
d->d->samples_to_skip = samples_to_skip;
return MPC_STATUS_OK;
}
/* rockbox: not used
void mpc_set_replay_level(mpc_demux * d, float level, mpc_bool_t use_gain,
mpc_bool_t use_title, mpc_bool_t clip_prevention)
{
float peak = use_title ? d->si.peak_title : d->si.peak_album;
float gain = use_title ? d->si.gain_title : d->si.gain_album;
if(!use_gain && !clip_prevention)
return;
if(!peak)
peak = 1.;
else
peak = (1 << 15) / pow(10, peak / (20 * 256));
if(!gain)
gain = 1.;
else
gain = pow(10, (level - gain / 256) / 20);
if(clip_prevention && (peak < gain || !use_gain))
gain = peak;
mpc_decoder_scale_output(d->d, gain);
}
*/
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