?? adpcm.c
字號:
} break; case CODEC_ID_ADPCM_IMA_WS: /* no per-block initialization; just start decoding the data */ while (src < buf + buf_size) { if (st) { *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F, 3); *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[0] & 0x0F, 3); } else { *samples++ = adpcm_ima_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F, 3); *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] & 0x0F, 3); } src++; } break; case CODEC_ID_ADPCM_XA: c->status[0].sample1 = c->status[0].sample2 = c->status[1].sample1 = c->status[1].sample2 = 0; while (buf_size >= 128) { xa_decode(samples, src, &c->status[0], &c->status[1], avctx->channels); src += 128; samples += 28 * 8; buf_size -= 128; } break; case CODEC_ID_ADPCM_EA: samples_in_chunk = AV_RL32(src); if (samples_in_chunk >= ((buf_size - 12) * 2)) { src += buf_size; break; } src += 4; current_left_sample = (int16_t)AV_RL16(src); src += 2; previous_left_sample = (int16_t)AV_RL16(src); src += 2; current_right_sample = (int16_t)AV_RL16(src); src += 2; previous_right_sample = (int16_t)AV_RL16(src); src += 2; for (count1 = 0; count1 < samples_in_chunk/28;count1++) { coeff1l = ea_adpcm_table[(*src >> 4) & 0x0F]; coeff2l = ea_adpcm_table[((*src >> 4) & 0x0F) + 4]; coeff1r = ea_adpcm_table[*src & 0x0F]; coeff2r = ea_adpcm_table[(*src & 0x0F) + 4]; src++; shift_left = ((*src >> 4) & 0x0F) + 8; shift_right = (*src & 0x0F) + 8; src++; for (count2 = 0; count2 < 28; count2++) { next_left_sample = (((*src & 0xF0) << 24) >> shift_left); next_right_sample = (((*src & 0x0F) << 28) >> shift_right); src++; next_left_sample = (next_left_sample + (current_left_sample * coeff1l) + (previous_left_sample * coeff2l) + 0x80) >> 8; next_right_sample = (next_right_sample + (current_right_sample * coeff1r) + (previous_right_sample * coeff2r) + 0x80) >> 8; previous_left_sample = current_left_sample; current_left_sample = av_clip_int16(next_left_sample); previous_right_sample = current_right_sample; current_right_sample = av_clip_int16(next_right_sample); *samples++ = (unsigned short)current_left_sample; *samples++ = (unsigned short)current_right_sample; } } break; case CODEC_ID_ADPCM_IMA_AMV: case CODEC_ID_ADPCM_IMA_SMJPEG: c->status[0].predictor = (int16_t)bytestream_get_le16(&src); c->status[0].step_index = bytestream_get_le16(&src); if (avctx->codec->id == CODEC_ID_ADPCM_IMA_AMV) src+=4; while (src < buf + buf_size) { char hi, lo; lo = *src & 0x0F; hi = (*src >> 4) & 0x0F; if (avctx->codec->id == CODEC_ID_ADPCM_IMA_AMV) FFSWAP(char, hi, lo); *samples++ = adpcm_ima_expand_nibble(&c->status[0], lo, 3); *samples++ = adpcm_ima_expand_nibble(&c->status[0], hi, 3); 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_SBPRO_4: case CODEC_ID_ADPCM_SBPRO_3: case CODEC_ID_ADPCM_SBPRO_2: if (!c->status[0].step_index) { /* the first byte is a raw sample */ *samples++ = 128 * (*src++ - 0x80); if (st) *samples++ = 128 * (*src++ - 0x80); c->status[0].step_index = 1; } if (avctx->codec->id == CODEC_ID_ADPCM_SBPRO_4) { while (src < buf + buf_size) { *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F, 4, 0); *samples++ = adpcm_sbpro_expand_nibble(&c->status[st], src[0] & 0x0F, 4, 0); src++; } } else if (avctx->codec->id == CODEC_ID_ADPCM_SBPRO_3) { while (src < buf + buf_size && samples + 2 < samples_end) { *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], (src[0] >> 5) & 0x07, 3, 0); *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], (src[0] >> 2) & 0x07, 3, 0); *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], src[0] & 0x03, 2, 0); src++; } } else { while (src < buf + buf_size && samples + 3 < samples_end) { *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], (src[0] >> 6) & 0x03, 2, 2); *samples++ = adpcm_sbpro_expand_nibble(&c->status[st], (src[0] >> 4) & 0x03, 2, 2); *samples++ = adpcm_sbpro_expand_nibble(&c->status[0], (src[0] >> 2) & 0x03, 2, 2); *samples++ = adpcm_sbpro_expand_nibble(&c->status[st], src[0] & 0x03, 2, 2); src++; } } break; case CODEC_ID_ADPCM_SWF: { GetBitContext gb; const int *table; int k0, signmask, nb_bits, count; int size = buf_size*8; init_get_bits(&gb, buf, size); //read bits & initial values nb_bits = get_bits(&gb, 2)+2; //av_log(NULL,AV_LOG_INFO,"nb_bits: %d\n", nb_bits); table = swf_index_tables[nb_bits-2]; k0 = 1 << (nb_bits-2); signmask = 1 << (nb_bits-1); while (get_bits_count(&gb) <= size - 22*avctx->channels) { for (i = 0; i < avctx->channels; i++) { *samples++ = c->status[i].predictor = get_sbits(&gb, 16); c->status[i].step_index = get_bits(&gb, 6); } for (count = 0; get_bits_count(&gb) <= size - nb_bits*avctx->channels && count < 4095; count++) { int i; for (i = 0; i < avctx->channels; i++) { // similar to IMA adpcm int delta = get_bits(&gb, 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 = av_clip(c->status[i].step_index, 0, 88); c->status[i].predictor = av_clip_int16(c->status[i].predictor); *samples++ = c->status[i].predictor; if (samples >= samples_end) { av_log(avctx, AV_LOG_ERROR, "allocated output buffer is too small\n"); return -1; } } } } src += buf_size; break; } case CODEC_ID_ADPCM_YAMAHA: while (src < buf + buf_size) { if (st) { *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], src[0] & 0x0F); *samples++ = adpcm_yamaha_expand_nibble(&c->status[1], (src[0] >> 4) & 0x0F); } else { *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], src[0] & 0x0F); *samples++ = adpcm_yamaha_expand_nibble(&c->status[0], (src[0] >> 4) & 0x0F); } src++; } break; case CODEC_ID_ADPCM_THP: { int table[2][16]; unsigned int samplecnt; int prev[2][2]; int ch; if (buf_size < 80) { av_log(avctx, AV_LOG_ERROR, "frame too small\n"); return -1; } src+=4; samplecnt = bytestream_get_be32(&src); for (i = 0; i < 32; i++) table[0][i] = (int16_t)bytestream_get_be16(&src); /* Initialize the previous sample. */ for (i = 0; i < 4; i++) prev[0][i] = (int16_t)bytestream_get_be16(&src); if (samplecnt >= (samples_end - samples) / (st + 1)) { av_log(avctx, AV_LOG_ERROR, "allocated output buffer is too small\n"); return -1; } for (ch = 0; ch <= st; ch++) { samples = (unsigned short *) data + ch; /* Read in every sample for this channel. */ for (i = 0; i < samplecnt / 14; i++) { int index = (*src >> 4) & 7; unsigned int exp = 28 - (*src++ & 15); int factor1 = table[ch][index * 2]; int factor2 = table[ch][index * 2 + 1]; /* Decode 14 samples. */ for (n = 0; n < 14; n++) { int32_t sampledat; if(n&1) sampledat= *src++ <<28; else sampledat= (*src&0xF0)<<24; sampledat = ((prev[ch][0]*factor1 + prev[ch][1]*factor2) >> 11) + (sampledat>>exp); *samples = av_clip_int16(sampledat); prev[ch][1] = prev[ch][0]; prev[ch][0] = *samples++; /* In case of stereo, skip one sample, this sample is for the other channel. */ samples += st; } } } /* In the previous loop, in case stereo is used, samples is increased exactly one time too often. */ samples -= st; break; } default: return -1; } *data_size = (uint8_t *)samples - (uint8_t *)data; return src - buf;}#ifdef CONFIG_ENCODERS#define ADPCM_ENCODER(id,name) \AVCodec name ## _encoder = { \ #name, \ CODEC_TYPE_AUDIO, \ id, \ sizeof(ADPCMContext), \ adpcm_encode_init, \ adpcm_encode_frame, \ adpcm_encode_close, \ NULL, \};#else#define ADPCM_ENCODER(id,name)#endif#ifdef CONFIG_DECODERS#define ADPCM_DECODER(id,name) \AVCodec name ## _decoder = { \ #name, \ CODEC_TYPE_AUDIO, \ id, \ sizeof(ADPCMContext), \ adpcm_decode_init, \ NULL, \ NULL, \ adpcm_decode_frame, \};#else#define ADPCM_DECODER(id,name)#endif#define ADPCM_CODEC(id, name) \ADPCM_ENCODER(id,name) ADPCM_DECODER(id,name)ADPCM_CODEC(CODEC_ID_ADPCM_4XM, adpcm_4xm);ADPCM_CODEC(CODEC_ID_ADPCM_CT, adpcm_ct);ADPCM_CODEC(CODEC_ID_ADPCM_EA, adpcm_ea);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_AMV, adpcm_ima_amv);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK3, adpcm_ima_dk3);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_DK4, adpcm_ima_dk4);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_QT, adpcm_ima_qt);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_SMJPEG, adpcm_ima_smjpeg);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WAV, adpcm_ima_wav);ADPCM_CODEC(CODEC_ID_ADPCM_IMA_WS, adpcm_ima_ws);ADPCM_CODEC(CODEC_ID_ADPCM_MS, adpcm_ms);ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_4, adpcm_sbpro_4);ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_3, adpcm_sbpro_3);ADPCM_CODEC(CODEC_ID_ADPCM_SBPRO_2, adpcm_sbpro_2);ADPCM_CODEC(CODEC_ID_ADPCM_SWF, adpcm_swf);ADPCM_CODEC(CODEC_ID_ADPCM_THP, adpcm_thp);ADPCM_CODEC(CODEC_ID_ADPCM_XA, adpcm_xa);ADPCM_CODEC(CODEC_ID_ADPCM_YAMAHA, adpcm_yamaha);#undef ADPCM_CODEC
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