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Move run level decode functionality to ff_wma_run_level_decode

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so that it can be reused for wmapro

Originally committed as revision 19171 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Sascha Sommer 2009-06-12 16:00:26 +00:00
parent e8c7f81cf2
commit c0e9b2e84f
3 changed files with 74 additions and 43 deletions
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61
libavcodec/wma.c
View File

@ -424,3 +424,64 @@ int ff_wma_end(AVCodecContext *avctx)
return 0;
}
/**
* Decode run level compressed coefficients.
* @param avctx codec context
* @param gb bitstream reader context
* @param vlc vlc table for get_vlc2
* @param level_table level codes
* @param run_table run codes
* @param version 0 for wma1,2 1 for wmapro
* @param ptr output buffer
* @param offset offset in the output buffer
* @param num_coefs number of input coefficents
* @param block_len input buffer length (2^n)
* @param frame_len_bits number of bits for escaped run codes
* @param coef_nb_bits number of bits for escaped level codes
* @return 0 on success, -1 otherwise
*/
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
VLC *vlc,
const uint16_t *level_table, const uint16_t *run_table,
int version, int16_t *ptr, int offset,
int num_coefs, int block_len, int frame_len_bits,
int coef_nb_bits)
{
int code, run, level, sign;
int16_t* eptr = ptr + num_coefs;
for(;;) {
code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
if (code < 0)
return -1;
if (code == 1) {
/* EOB */
break;
} else if (code == 0) {
/* escape */
level = get_bits(gb, coef_nb_bits);
/* NOTE: this is rather suboptimal. reading
block_len_bits would be better */
run = get_bits(gb, frame_len_bits);
} else {
/* normal code */
run = run_table[code];
level = level_table[code];
}
sign = get_bits1(gb);
if (!sign)
level = -level;
ptr += run;
if (ptr >= eptr)
{
av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
break;
}
*ptr++ = level;
/* NOTE: EOB can be omitted */
if (ptr >= eptr)
break;
}
return 0;
}

6
libavcodec/wma.h
View File

@ -148,5 +148,11 @@ int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version,
int ff_wma_init(AVCodecContext * avctx, int flags2);
int ff_wma_total_gain_to_bits(int total_gain);
int ff_wma_end(AVCodecContext *avctx);
int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
VLC *vlc,
const uint16_t *level_table, const uint16_t *run_table,
int version, int16_t *ptr, int offset,
int num_coefs, int block_len, int frame_len_bits,
int coef_nb_bits);
#endif /* AVCODEC_WMA_H */

50
libavcodec/wmadec.c
View File

@ -349,7 +349,7 @@ static void wma_window(WMACodecContext *s, float *out)
*/
static int wma_decode_block(WMACodecContext *s)
{
int n, v, a, ch, code, bsize;
int n, v, a, ch, bsize;
int coef_nb_bits, total_gain;
int nb_coefs[MAX_CHANNELS];
float mdct_norm;
@ -485,53 +485,17 @@ static int wma_decode_block(WMACodecContext *s)
/* parse spectral coefficients : just RLE encoding */
for(ch = 0; ch < s->nb_channels; ch++) {
if (s->channel_coded[ch]) {
VLC *coef_vlc;
int level, run, sign, tindex;
int16_t *ptr, *eptr;
const uint16_t *level_table, *run_table;
int tindex;
int16_t* ptr = &s->coefs1[ch][0];
/* special VLC tables are used for ms stereo because
there is potentially less energy there */
tindex = (ch == 1 && s->ms_stereo);
coef_vlc = &s->coef_vlc[tindex];
run_table = s->run_table[tindex];
level_table = s->level_table[tindex];
/* XXX: optimize */
ptr = &s->coefs1[ch][0];
eptr = ptr + nb_coefs[ch];
memset(ptr, 0, s->block_len * sizeof(int16_t));
for(;;) {
code = get_vlc2(&s->gb, coef_vlc->table, VLCBITS, VLCMAX);
if (code < 0)
return -1;
if (code == 1) {
/* EOB */
break;
} else if (code == 0) {
/* escape */
level = get_bits(&s->gb, coef_nb_bits);
/* NOTE: this is rather suboptimal. reading
block_len_bits would be better */
run = get_bits(&s->gb, s->frame_len_bits);
} else {
/* normal code */
run = run_table[code];
level = level_table[code];
}
sign = get_bits1(&s->gb);
if (!sign)
level = -level;
ptr += run;
if (ptr >= eptr)
{
av_log(NULL, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
break;
}
*ptr++ = level;
/* NOTE: EOB can be omitted */
if (ptr >= eptr)
break;
}
ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
s->level_table[tindex], s->run_table[tindex],
0, ptr, 0, nb_coefs[ch],
s->block_len, s->frame_len_bits, coef_nb_bits);
}
if (s->version == 1 && s->nb_channels >= 2) {
align_get_bits(&s->gb);