diff options
Diffstat (limited to 'src/libffmpeg/libavcodec/adpcm.c')
| -rw-r--r-- | src/libffmpeg/libavcodec/adpcm.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/libffmpeg/libavcodec/adpcm.c b/src/libffmpeg/libavcodec/adpcm.c index 0755e24fe..043c4d4b2 100644 --- a/src/libffmpeg/libavcodec/adpcm.c +++ b/src/libffmpeg/libavcodec/adpcm.c @@ -17,6 +17,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "avcodec.h" +#include "bitstream.h" /** * @file adpcm.c @@ -103,6 +104,19 @@ static int ea_adpcm_table[] = { 3, 4, 7, 8, 10, 11, 0, -1, -3, -4 }; +static int ct_adpcm_table[8] = { + 0x00E6, 0x00E6, 0x00E6, 0x00E6, + 0x0133, 0x0199, 0x0200, 0x0266 +}; + +// padded to zero where table size is less then 16 +static int swf_index_tables[4][16] = { + /*2*/ { -1, 2 }, + /*3*/ { -1, -1, 2, 4 }, + /*4*/ { -1, -1, -1, -1, 2, 4, 6, 8 }, + /*5*/ { -1, -1, -1, -1, -1, -1, -1, -1, 1, 2, 4, 6, 8, 10, 13, 16 } +}; + /* end of tables */ typedef struct ADPCMChannelStatus { @@ -124,6 +138,10 @@ typedef struct ADPCMContext { int channel; /* for stereo MOVs, decode left, then decode right, then tell it's decoded */ ADPCMChannelStatus status[2]; short sample_buffer[32]; /* hold left samples while waiting for right samples */ + + /* SWF only */ + int nb_bits; + int nb_samples; } ADPCMContext; /* XXX: implement encoding */ @@ -361,6 +379,9 @@ static int adpcm_decode_init(AVCodecContext * avctx) c->status[0].step = c->status[1].step = 0; switch(avctx->codec->id) { + case CODEC_ID_ADPCM_CT: + c->status[0].step = c->status[1].step = 511; + break; default: break; } @@ -411,6 +432,37 @@ static inline short adpcm_ms_expand_nibble(ADPCMChannelStatus *c, char nibble) return (short)predictor; } +static inline short adpcm_ct_expand_nibble(ADPCMChannelStatus *c, char nibble) +{ + int predictor; + int sign, delta, diff; + int new_step; + + sign = nibble & 8; + delta = nibble & 7; + /* perform direct multiplication instead of series of jumps proposed by + * the reference ADPCM implementation since modern CPUs can do the mults + * quickly enough */ + diff = ((2 * delta + 1) * c->step) >> 3; + predictor = c->predictor; + /* predictor update is not so trivial: predictor is multiplied on 254/256 before updating */ + if(sign) + predictor = ((predictor * 254) >> 8) - diff; + else + predictor = ((predictor * 254) >> 8) + diff; + /* calculate new step and clamp it to range 511..32767 */ + new_step = (ct_adpcm_table[nibble & 7] * c->step) >> 8; + c->step = new_step; + if(c->step < 511) + c->step = 511; + if(c->step > 32767) + c->step = 32767; + + CLAMP_TO_SHORT(predictor); + c->predictor = predictor; + return (short)predictor; +} + static void xa_decode(short *out, const unsigned char *in, ADPCMChannelStatus *left, ADPCMChannelStatus *right, int inc) { @@ -840,6 +892,92 @@ static int adpcm_decode_frame(AVCodecContext *avctx, src++; } break; + case CODEC_ID_ADPCM_CT: + while (src < buf + buf_size) { + if (st) { + *samples++ = adpcm_ct_expand_nibble(&c->status[0], + (src[0] >> 4) & 0x0F); + *samples++ = adpcm_ct_expand_nibble(&c->status[1], + src[0] & 0x0F); + } else { + *samples++ = adpcm_ct_expand_nibble(&c->status[0], + (src[0] >> 4) & 0x0F); + *samples++ = adpcm_ct_expand_nibble(&c->status[0], + src[0] & 0x0F); + } + src++; + } + break; + case CODEC_ID_ADPCM_SWF: + { + GetBitContext gb; + int *table; + int k0, signmask; + int size = buf_size*8; + + init_get_bits(&gb, buf, size); + + // first frame, read bits & inital values + if (!c->nb_bits) + { + c->nb_bits = get_bits(&gb, 2)+2; +// av_log(NULL,AV_LOG_INFO,"nb_bits: %d\n", c->nb_bits); + } + + table = swf_index_tables[c->nb_bits-2]; + k0 = 1 << (c->nb_bits-2); + signmask = 1 << (c->nb_bits-1); + + while (get_bits_count(&gb) <= size) + { + int i; + + c->nb_samples++; + // wrap around at every 4096 samples... + if ((c->nb_samples & 0xfff) == 1) + { + for (i = 0; i <= st; i++) + { + *samples++ = c->status[i].predictor = get_sbits(&gb, 16); + c->status[i].step_index = get_bits(&gb, 6); + } + } + + // similar to IMA adpcm + for (i = 0; i <= st; i++) + { + int delta = get_bits(&gb, c->nb_bits); + int step = step_table[c->status[i].step_index]; + long vpdiff = 0; // vpdiff = (delta+0.5)*step/4 + int k = k0; + + do { + if (delta & k) + vpdiff += step; + step >>= 1; + k >>= 1; + } while(k); + vpdiff += step; + + if (delta & signmask) + c->status[i].predictor -= vpdiff; + else + c->status[i].predictor += vpdiff; + + c->status[i].step_index += table[delta & (~signmask)]; + + c->status[i].step_index = clip(c->status[i].step_index, 0, 88); + c->status[i].predictor = clip(c->status[i].predictor, -32768, 32767); + + *samples++ = c->status[i].predictor; + } + } + +// src += get_bits_count(&gb)*8; + src += size; + + break; + } default: return -1; } @@ -895,5 +1033,7 @@ ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm); ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa); ADPCM_CODEC(CODEC_ID_ADPCM_ADX, adpcm_adx); ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea); +ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct); +ADPCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf); #undef ADPCM_CODEC |