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Read the bitstream where the data is actually needed instead of doing it in unpack_input() 

Originally committed as revision 13162 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vitor Sessak 2008-05-15 18:31:55 +00:00
parent ab5e6526a3
commit ae9b8019ec
1 changed files with 18 additions and 51 deletions
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69
libavcodec/ra144.c
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@ -32,8 +32,6 @@
/* internal globals */
typedef struct {
unsigned int resetflag, val, oldval;
unsigned int unpacked[28]; /* buffer for unpacked input */
unsigned int *iptr; /* pointer to current input (from unpacked) */
unsigned int gval;
unsigned short *gsp;
unsigned int gbuf1[8];
@ -125,25 +123,21 @@ static void do_voice(int *a1, int *a2)
/* do quarter-block output */
static void do_output_subblock(Real144_internal *glob, unsigned int x)
static void do_output_subblock(Real144_internal *glob, unsigned int x, GetBitContext *gb)
{
int a, b, c, d, e, f, g;
int e, f, g;
int a = get_bits(gb, 7);
int d = get_bits(gb, 8);
int b = get_bits(gb, 7);
int c = get_bits(gb, 7);
if (x == 1)
memset(glob->buffer, 0, 20);
if ((*glob->iptr) == 0)
a = 0;
else
a = (*glob->iptr) + HALFBLOCK - 1;
glob->iptr++;
b = *(glob->iptr++);
c = *(glob->iptr++);
d = *(glob->iptr++);
if (a)
if (a) {
a += HALFBLOCK - 1;
rotate_block(glob->buffer_2, glob->buffer_a, a);
}
memcpy(glob->buffer_b, etable1 + b * BLOCKSIZE, BLOCKSIZE * 2);
e = ((ftable1[b] >> 4) *glob->gval) >> 8;
@ -268,31 +262,6 @@ static void final(Real144_internal *glob, short *i1, short *i2, void *out,
memcpy(statbuf, ptr, 20);
}
/* Decode 20-byte input */
static void unpack_input(const unsigned char *input, unsigned int *output)
{
int i;
static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
GetBitContext gb;
init_get_bits(&gb, input, 20 * 8);
for (i=0; i<10; i++)
output[i+1] = get_bits(&gb, sizes[i]);
output[0] = get_bits(&gb, 5);
output += 11;
for (i=0; i<4; i++) {
output[0] = get_bits(&gb, 7);
output[3] = get_bits(&gb, 8);
output[1] = get_bits(&gb, 7);
output[2] = get_bits(&gb, 7);
output += 4;
}
}
static unsigned int rms(int *data, int f)
{
int *c;
@ -441,31 +410,29 @@ static int ra144_decode_frame(AVCodecContext * avctx,
void *vdata, int *data_size,
const uint8_t * buf, int buf_size)
{
static const uint8_t sizes[10] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
unsigned int a, b, c;
int i;
signed short *shptr;
unsigned int *lptr;
const short **dptr;
int16_t *datao;
int16_t *data = vdata;
Real144_internal *glob = avctx->priv_data;
GetBitContext gb;
if(buf_size == 0)
return 0;
datao = data;
unpack_input(buf, glob->unpacked);
glob->iptr = glob->unpacked;
glob->val = decodeval[(*(glob->iptr++)) << 1];
init_get_bits(&gb, buf, 20 * 8);
dptr = decodetable;
lptr = glob->swapbuf1;
while (lptr<glob->swapbuf1 + 10)
*(lptr++) = (*(dptr++))[(*(glob->iptr++)) << 1];
for (i=0; i<10; i++)
// "<< 1"? Doesn't this make one value out of two of the table useless?
glob->swapbuf1[i] = decodetable[i][get_bits(&gb, sizes[i]) << 1];
do_voice(glob->swapbuf1, glob->swapbuf2);
glob->val = decodeval[get_bits(&gb, 5) << 1]; // Useless table entries?
a = t_sqrt(glob->val*glob->oldval) >> 12;
for (c=0; c < NBLOCKS; c++) {
@ -492,7 +459,7 @@ static int ra144_decode_frame(AVCodecContext * avctx,
for (b=0, c=0; c<4; c++) {
glob->gval = glob->gbuf1[c * 2];
glob->gsp = glob->gbuf2 + b;
do_output_subblock(glob, glob->resetflag);
do_output_subblock(glob, glob->resetflag, &gb);
glob->resetflag = 0;
shptr = glob->output_buffer;