adpcm.c

ffmpeg移植到symbian的全部源代码

        if (cs->step_index > 88) cs->step_index = 88;

        m= (buf_size - (src - buf))>>st;
        for(i=0; i<m; i++) {
            *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] & 0x0F, 4);
            if (st)
                *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] & 0x0F, 4);
            *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[i] >> 4, 4);
            if (st)
                *samples++ = adpcm_ima_expand_nibble(&c->status[1], src[i+m] >> 4, 4);
        }

        src += m<<st;

        break;
    case CODEC_ID_ADPCM_MS:
        if (avctx->block_align != 0 && buf_size > avctx->block_align)
            buf_size = avctx->block_align;
        n = buf_size - 7 * avctx->channels;
        if (n < 0)
            return -1;
        block_predictor[0] = av_clip(*src++, 0, 6);
        block_predictor[1] = 0;
        if (st)
            block_predictor[1] = av_clip(*src++, 0, 6);
        c->status[0].idelta = (int16_t)bytestream_get_le16(&src);
        if (st){
            c->status[1].idelta = (int16_t)bytestream_get_le16(&src);
        }
        c->status[0].coeff1 = AdaptCoeff1[block_predictor[0]];
        c->status[0].coeff2 = AdaptCoeff2[block_predictor[0]];
        c->status[1].coeff1 = AdaptCoeff1[block_predictor[1]];
        c->status[1].coeff2 = AdaptCoeff2[block_predictor[1]];

        c->status[0].sample1 = bytestream_get_le16(&src);
        if (st) c->status[1].sample1 = bytestream_get_le16(&src);
        c->status[0].sample2 = bytestream_get_le16(&src);
        if (st) c->status[1].sample2 = bytestream_get_le16(&src);

        *samples++ = c->status[0].sample2;
        if (st) *samples++ = c->status[1].sample2;
        *samples++ = c->status[0].sample1;
        if (st) *samples++ = c->status[1].sample1;
        for(;n>0;n--) {
            *samples++ = adpcm_ms_expand_nibble(&c->status[0 ], src[0] >> 4  );
            *samples++ = adpcm_ms_expand_nibble(&c->status[st], src[0] & 0x0F);
            src ++;
        }
        break;
    case CODEC_ID_ADPCM_IMA_DK4:
        if (avctx->block_align != 0 && buf_size > avctx->block_align)
            buf_size = avctx->block_align;

        c->status[0].predictor  = (int16_t)bytestream_get_le16(&src);
        c->status[0].step_index = *src++;
        src++;
        *samples++ = c->status[0].predictor;
        if (st) {
            c->status[1].predictor  = (int16_t)bytestream_get_le16(&src);
            c->status[1].step_index = *src++;
            src++;
            *samples++ = c->status[1].predictor;
        }
        while (src < buf + buf_size) {

            /* take care of the top nibble (always left or mono channel) */
            *samples++ = adpcm_ima_expand_nibble(&c->status[0],
                src[0] >> 4, 3);

            /* take care of the bottom nibble, which is right sample for
             * stereo, or another mono sample */
            if (st)
                *samples++ = adpcm_ima_expand_nibble(&c->status[1],
                    src[0] & 0x0F, 3);
            else
                *samples++ = adpcm_ima_expand_nibble(&c->status[0],
                    src[0] & 0x0F, 3);

            src++;
        }
        break;
    case CODEC_ID_ADPCM_IMA_DK3:
        if (avctx->block_align != 0 && buf_size > avctx->block_align)
            buf_size = avctx->block_align;

        if(buf_size + 16 > (samples_end - samples)*3/8)
            return -1;

        c->status[0].predictor  = (int16_t)AV_RL16(src + 10);
        c->status[1].predictor  = (int16_t)AV_RL16(src + 12);
        c->status[0].step_index = src[14];
        c->status[1].step_index = src[15];
        /* sign extend the predictors */
        src += 16;
        diff_channel = c->status[1].predictor;

        /* the DK3_GET_NEXT_NIBBLE macro issues the break statement when
         * the buffer is consumed */
        while (1) {

            /* for this algorithm, c->status[0] is the sum channel and
             * c->status[1] is the diff channel */

            /* process the first predictor of the sum channel */
            DK3_GET_NEXT_NIBBLE();
            adpcm_ima_expand_nibble(&c->status[0], nibble, 3);

            /* process the diff channel predictor */
            DK3_GET_NEXT_NIBBLE();
            adpcm_ima_expand_nibble(&c->status[1], nibble, 3);

            /* process the first pair of stereo PCM samples */
            diff_channel = (diff_channel + c->status[1].predictor) / 2;
            *samples++ = c->status[0].predictor + c->status[1].predictor;
            *samples++ = c->status[0].predictor - c->status[1].predictor;

            /* process the second predictor of the sum channel */
            DK3_GET_NEXT_NIBBLE();
            adpcm_ima_expand_nibble(&c->status[0], nibble, 3);

            /* process the second pair of stereo PCM samples */
            diff_channel = (diff_channel + c->status[1].predictor) / 2;
            *samples++ = c->status[0].predictor + c->status[1].predictor;
            *samples++ = c->status[0].predictor - c->status[1].predictor;
        }
        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  , 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  , 3);
                *samples++ = adpcm_ima_expand_nibble(&c->status[0],
                    src[0] & 0x0F, 3);
            }

            src++;
        }
        break;
    case CODEC_ID_ADPCM_XA:
        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_IMA_EA_EACS:
        samples_in_chunk = bytestream_get_le32(&src) >> (1-st);

        if (samples_in_chunk > buf_size-4-(8<<st)) {
            src += buf_size - 4;
            break;
        }

        for (i=0; i<=st; i++)
            c->status[i].step_index = bytestream_get_le32(&src);
        for (i=0; i<=st; i++)
            c->status[i].predictor  = bytestream_get_le32(&src);

        for (; samples_in_chunk; samples_in_chunk--, src++) {
            *samples++ = adpcm_ima_expand_nibble(&c->status[0],  *src>>4,   3);
            *samples++ = adpcm_ima_expand_nibble(&c->status[st], *src&0x0F, 3);
        }
        break;
    case CODEC_ID_ADPCM_IMA_EA_SEAD:
        for (; src < buf+buf_size; src++) {
            *samples++ = adpcm_ima_expand_nibble(&c->status[0], src[0] >> 4, 6);
            *samples++ = adpcm_ima_expand_nibble(&c->status[st],src[0]&0x0F, 6);
        }
        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)bytestream_get_le16(&src);
        previous_left_sample  = (int16_t)bytestream_get_le16(&src);
        current_right_sample  = (int16_t)bytestream_get_le16(&src);
        previous_right_sample = (int16_t)bytestream_get_le16(&src);

        for (count1 = 0; count1 < samples_in_chunk/28;count1++) {
            coeff1l = ea_adpcm_table[ *src >> 4       ];
            coeff2l = ea_adpcm_table[(*src >> 4  ) + 4];
            coeff1r = ea_adpcm_table[*src & 0x0F];
            coeff2r = ea_adpcm_table[(*src & 0x0F) + 4];
            src++;

            shift_left  = (*src >> 4  ) + 8;
            shift_right = (*src & 0x0F) + 8;
            src++;

            for (count2 = 0; count2 < 28; count2++) {
                next_left_sample  = (int32_t)((*src & 0xF0) << 24) >> shift_left;
                next_right_sample = (int32_t)((*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_EA_MAXIS_XA:
        for(channel = 0; channel < avctx->channels; channel++) {
            for (i=0; i<2; i++)
                coeff[channel][i] = ea_adpcm_table[(*src >> 4) + 4*i];
            shift[channel] = (*src & 0x0F) + 8;
            src++;
        }
        for (count1 = 0; count1 < (buf_size - avctx->channels) / avctx->channels; count1++) {
            for(i = 4; i >= 0; i-=4) { /* Pairwise samples LL RR (st) or LL LL (mono) */
                for(channel = 0; channel < avctx->channels; channel++) {
                    int32_t sample = (int32_t)(((*(src+channel) >> i) & 0x0F) << 0x1C) >> shift[channel];
                    sample = (sample +
                             c->status[channel].sample1 * coeff[channel][0] +
                             c->status[channel].sample2 * coeff[channel][1] + 0x80) >> 8;
                    c->status[channel].sample2 = c->status[channel].sample1;
                    c->status[channel].sample1 = av_clip_int16(sample);
                    *samples++ = c->status[channel].sample1;
                }
            }
            src+=avctx->channels;
        }
        break;
    case CODEC_ID_ADPCM_EA_R1:
    case CODEC_ID_ADPCM_EA_R2:
    case CODEC_ID_ADPCM_EA_R3: {
        /* channel numbering
           2chan: 0=fl, 1=fr
           4chan: 0=fl, 1=rl, 2=fr, 3=rr
           6chan: 0=fl, 1=c,  2=fr, 3=rl,  4=rr, 5=sub */
        const int big_endian = avctx->codec->id == CODEC_ID_ADPCM_EA_R3;
        int32_t previous_sample, current_sample, next_sample;
        int32_t coeff1, coeff2;
        uint8_t shift;
        unsigned int channel;
        uint16_t *samplesC;
        const uint8_t *srcC;

        samples_in_chunk = (big_endian ? bytestream_get_be32(&src)
                                       : bytestream_get_le32(&src)) / 28;
        if (samples_in_chunk > UINT32_MAX/(28*avctx->channels) ||
            28*samples_in_chunk*avctx->channels > samples_end-samples) {
            src += buf_size - 4;
            break;
        }

        for (channel=0; channel<avctx->channels; channel++) {
            srcC = src + (big_endian ? bytestream_get_be32(&src)
                                     : bytestream_get_le32(&src))
                       + (avctx->channels-channel-1) * 4;
#ifndef __CW32__
            samplesC = samples + channel;
#else
            samplesC = (uint16_t*)(samples + channel);
#endif

            if (avctx->codec->id == CODEC_ID_ADPCM_EA_R1) {
                current_sample  = (int16_t)bytestream_get_le16(&srcC);
                previous_sample = (int16_t)bytestream_get_le16(&srcC);
            } else {
                current_sample  = c->status[channel].predictor;
                previous_sample = c->status[channel].prev_sample;
            }

            for (count1=0; count1<samples_in_chunk; count1++) {
                if (*srcC == 0xEE) {  /* only seen in R2 and R3 */
                    srcC++;
                    current_sample  = (int16_t)bytestream_get_be16(&srcC);
                    previous_sample = (int16_t)bytestream_get_be16(&srcC);

                    for (count2=0; count2<28; count2++) {
                        *samplesC = (int16_t)bytestream_get_be16(&srcC);
                        samplesC += avctx->channels;
                    }
                } else {
                    coeff1 = ea_adpcm_table[ *srcC>>4     ];
                    coeff2 = ea_adpcm_table[(*srcC>>4) + 4];
                    shift = (*srcC++ & 0x0F) + 8;

                    for (count2=0; count2<28; count2++) {
                        if (count2 & 1)
                            next_sample = (int32_t)((*srcC++ & 0x0F) << 28) >> shift;
                        else
                            next_sample = (int32_t)((*srcC   & 0xF0) << 24) >> shift;

                        next_sample += (current_sample  * coeff1) +
                                       (previous_sample * coeff2);
                        next_sample = av_clip_int16(next_sample >> 8);

                        previous_sample = current_sample;
                        current_sample  = next_sample;
                        *samplesC = current_sample;
                        samplesC += avctx->channels;
                    }
                }
            }

            if (avctx->codec->id != CODEC_ID_ADPCM_EA_R1) {
                c->status[channel].predictor   = current_sample;
                c->status[channel].prev_sample = previous_sample;
            }
        }

        src = src + buf_size - (4 + 4*avctx->channels);
        samples += 28 * samples_in_chunk * avctx->channels;
        break;
    }
    case CODEC_ID_ADPCM_EA_XAS:
        if (samples_end-samples < 32*4*avctx->channels
            || buf_size < (4+15)*4*avctx->channels) {
            src += buf_size;
            break;
        }
        for (channel=0; channel<avctx->channels; channel++) {
            int coeff[2][4], shift[4];
            short *s2, *s = &samples[channel];
            for (n=0; n<4; n++, s+=32*avctx->channels) {
                for (i=0; i<2; i++)
                    coeff[i][n] = ea_adpcm_table[(src[0]&0x0F)+4*i];
                shift[n] = (src[2]&0x0F) + 8;
                for (s2=s, i=0; i<2; i++, src+=2, s2+=avctx->channels)
                    s2[0] = (src[0]&0xF0) + (src[1]<<8);
            }

            for (m=2; m<32; m+=2) {
                s = &samples[m*avctx->channels + channel];
                for (n=0; n<4; n++, src++, s+=32*avctx->channels) {
                    for (s2=s, i=0; i<8; i+=4, s2+=avctx->channels) {
                        int level = (int32_t)((*src & (0xF0>>i)) << (24+i)) >> shift[n];