devs/foxbox
1
0
Fork 0
forked from len0rd/rockbox
Code Pull requests Activity

Optimization of mpc's buffering routines through using the maximum possible buffer size. This reduces read access calls.

Browse source 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28198 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2010-10-02 17:52:12 +00:00
parent 32838e96d0
commit 2ddcd7fd94
1 changed files with 13 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

25
apps/codecs/libmusepack/mpc_demux.c
View file

@ -47,8 +47,11 @@
/// be adapted so this value is never exceeded.
#define MAX_SEEK_TABLE_SIZE 8192
// defines
#define MAX_BUFFER_SIZE (DEMUX_BUFFER_SIZE + MAX_FRAME_SIZE)
// globals
static mpc_uint8_t g_buffer[DEMUX_BUFFER_SIZE + MAX_FRAME_SIZE];
static mpc_uint8_t g_buffer[MAX_BUFFER_SIZE];
static mpc_seek_t g_seek_table[MAX_SEEK_TABLE_SIZE];
static mpc_demux g_mpc_demux IBSS_ATTR;
@ -73,16 +76,16 @@ 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;
- ((8 - d->bits_reader.count) >> 3);
mpc_int32_t offset = 0;
if (min_bytes == 0 || min_bytes > DEMUX_BUFFER_SIZE ||
if (min_bytes == 0 || min_bytes > MAX_BUFFER_SIZE ||
(unread_bytes < min_bytes && flags & MPC_BUFFER_FULL))
min_bytes = DEMUX_BUFFER_SIZE;
min_bytes = MAX_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;
mpc_uint32_t bytes_free = MAX_BUFFER_SIZE - d->bytes_total;
if (flags & MPC_BUFFER_SWAP) {
bytes2read &= -1 << 2;
@ -137,13 +140,12 @@ mpc_demux_seek(mpc_demux * d, mpc_seek_t fpos, mpc_uint32_t min_bytes) {
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);
mpc_demux_fill(d, MAX_BUFFER_SIZE, MPC_BUFFER_FULL | MPC_BUFFER_SWAP);
else
mpc_demux_fill(d, DEMUX_BUFFER_SIZE, 0);
mpc_demux_fill(d, MAX_BUFFER_SIZE, MPC_BUFFER_FULL);
d->bits_reader.buff += buf_fpos >> 3;
d->bits_reader.count = 8 - (buf_fpos & 7);
}
@ -448,7 +450,7 @@ static mpc_status mpc_demux_header(mpc_demux * d)
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)
if (b.size > (mpc_uint64_t) MAX_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){
@ -545,8 +547,7 @@ mpc_status mpc_demux_decode(mpc_demux * d, mpc_frame_info * i)
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);
mpc_demux_fill(d, MAX_FRAME_SIZE, MPC_BUFFER_FULL);
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;