roqvideo.c

arm平台下的H264编码和解码源代码

    }

    pa = ri->current_frame.data[2] + (y/2) * (ri->c_stride) + x/2;
    pb = ri->last_frame.data[2] + (my/2) * (ri->c_stride) + (mx + 1)/2;
    for(i = 0; i < 4; i++) {
        pa[0] = pb[0];
        pa[1] = pb[1];
        pa[2] = pb[2];
        pa[3] = pb[3];
        pa += ri->c_stride;
        pb += ri->c_stride;
    }
#else
    hw = ri->c_stride;
    pa = ri->current_frame.data[1] + (y * ri->y_stride)/4 + x/2;
    pb = ri->last_frame.data[1] + (my/2) * (ri->y_stride/2) + (mx + 1)/2;
    for(j = 0; j < 2; j++) {
        for(i = 0; i < 4; i++) {
            switch(((my & 0x01) << 1) | (mx & 0x01)) {

            case 0:
                pa[0] = pb[0];
                pa[1] = pb[1];
                pa[2] = pb[2];
                pa[3] = pb[3];
                break;

            case 1:
                pa[0] = avg2(pb[0], pb[1]);
                pa[1] = avg2(pb[1], pb[2]);
                pa[2] = avg2(pb[2], pb[3]);
                pa[3] = avg2(pb[3], pb[4]);
                break;
 
            case 2:
                pa[0] = avg2(pb[0], pb[hw]);
                pa[1] = avg2(pb[1], pb[hw+1]);
                pa[2] = avg2(pb[2], pb[hw+2]);
                pa[3] = avg2(pb[3], pb[hw+3]);
                break;

            case 3:
                pa[0] = avg4(pb[0], pb[1], pb[hw], pb[hw+1]);
                pa[1] = avg4(pb[1], pb[2], pb[hw+1], pb[hw+2]);
                pa[2] = avg4(pb[2], pb[3], pb[hw+2], pb[hw+3]);
                pa[3] = avg4(pb[3], pb[4], pb[hw+3], pb[hw+4]);
                break;
            }
            pa += ri->c_stride;
            pb += ri->c_stride;
        }

        pa = ri->current_frame.data[2] + (y * ri->y_stride)/4 + x/2;
        pb = ri->last_frame.data[2] + (my/2) * (ri->y_stride/2) + (mx + 1)/2;
    }
#endif
}

static void roqvideo_decode_frame(RoqContext *ri)
{
    unsigned int chunk_id = 0, chunk_arg = 0;
    unsigned long chunk_size = 0;
    int i, j, k, nv1, nv2, vqflg = 0, vqflg_pos = -1;
    int vqid, bpos, xpos, ypos, xp, yp, x, y;
    int frame_stats[2][4] = {{0},{0}};
    roq_qcell *qcell;
    unsigned char *buf = ri->buf;
    unsigned char *buf_end = ri->buf + ri->size;

    while (buf < buf_end) {
        chunk_id = get_word(buf);
        chunk_size = get_long(buf);
        chunk_arg = get_word(buf);

        if(chunk_id == RoQ_QUAD_VQ)
            break;
        if(chunk_id == RoQ_QUAD_CODEBOOK) {
            if((nv1 = chunk_arg >> 8) == 0)
                nv1 = 256;
            if((nv2 = chunk_arg & 0xff) == 0 && nv1 * 6 < chunk_size)
                nv2 = 256;
            for(i = 0; i < nv1; i++) {
                ri->cells[i].y0 = get_byte(buf);
                ri->cells[i].y1 = get_byte(buf);
                ri->cells[i].y2 = get_byte(buf);
                ri->cells[i].y3 = get_byte(buf);
                ri->cells[i].u = get_byte(buf);
                ri->cells[i].v = get_byte(buf);
            }
            for(i = 0; i < nv2; i++)
                for(j = 0; j < 4; j++)
                    ri->qcells[i].idx[j] = get_byte(buf);
        }
    }

    bpos = xpos = ypos = 0;
    while(bpos < chunk_size) {
        for (yp = ypos; yp < ypos + 16; yp += 8)
            for (xp = xpos; xp < xpos + 16; xp += 8) {
                if (vqflg_pos < 0) {
                    vqflg = buf[bpos++]; vqflg |= (buf[bpos++] << 8);
                    vqflg_pos = 7;
                }
                vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
                frame_stats[0][vqid]++;
                vqflg_pos--;

                switch(vqid) {
                case RoQ_ID_MOT:
                    apply_motion_8x8(ri, xp, yp, 0, 8, 8);
                    break;
                case RoQ_ID_FCC:
                    apply_motion_8x8(ri, xp, yp, buf[bpos++], chunk_arg >> 8,
                        chunk_arg & 0xff);
                    break;
                case RoQ_ID_SLD:
                    qcell = ri->qcells + buf[bpos++];
                    apply_vector_4x4(ri, xp, yp, ri->cells + qcell->idx[0]);
                    apply_vector_4x4(ri, xp+4, yp, ri->cells + qcell->idx[1]);
                    apply_vector_4x4(ri, xp, yp+4, ri->cells + qcell->idx[2]);
                    apply_vector_4x4(ri, xp+4, yp+4, ri->cells + qcell->idx[3]);
                    break;
                case RoQ_ID_CCC:
                    for (k = 0; k < 4; k++) {
                        x = xp; y = yp;
                        if(k & 0x01) x += 4;
                        if(k & 0x02) y += 4;

                        if (vqflg_pos < 0) {
                            vqflg = buf[bpos++];
                            vqflg |= (buf[bpos++] << 8);
                            vqflg_pos = 7;
                        }
                        vqid = (vqflg >> (vqflg_pos * 2)) & 0x3;
                        frame_stats[1][vqid]++;
                        vqflg_pos--;
                        switch(vqid) {
                        case RoQ_ID_MOT:
                            apply_motion_4x4(ri, x, y, 0, 8, 8);
                            break;
                        case RoQ_ID_FCC:
                            apply_motion_4x4(ri, x, y, buf[bpos++], 
                                chunk_arg >> 8, chunk_arg & 0xff);
                            break;
                        case RoQ_ID_SLD:
                            qcell = ri->qcells + buf[bpos++];
                            apply_vector_2x2(ri, x, y, ri->cells + qcell->idx[0]);
                            apply_vector_2x2(ri, x+2, y, ri->cells + qcell->idx[1]);
                            apply_vector_2x2(ri, x, y+2, ri->cells + qcell->idx[2]);
                            apply_vector_2x2(ri, x+2, y+2, ri->cells + qcell->idx[3]);
                            break;
                        case RoQ_ID_CCC:
                            apply_vector_2x2(ri, x, y, ri->cells + buf[bpos]);
                            apply_vector_2x2(ri, x+2, y, ri->cells + buf[bpos+1]);
                            apply_vector_2x2(ri, x, y+2, ri->cells + buf[bpos+2]);
                            apply_vector_2x2(ri, x+2, y+2, ri->cells + buf[bpos+3]);
                            bpos += 4;
                            break;
                        }
                    }
                    break;
                default:
                    av_log(ri->avctx, AV_LOG_ERROR, "Unknown vq code: %d\n", vqid);
            }
        }

        xpos += 16;
        if (xpos >= ri->avctx->width) {
            xpos -= ri->avctx->width;
            ypos += 16;
        }
        if(ypos >= ri->avctx->height)
            break;
    }
}


static int roq_decode_init(AVCodecContext *avctx)
{
    RoqContext *s = avctx->priv_data;
    int i;

    s->avctx = avctx;
    s->first_frame = 1;
    avctx->pix_fmt = PIX_FMT_YUV420P;
    avctx->has_b_frames = 0;
    dsputil_init(&s->dsp, avctx);

    uiclp = uiclip+512;
    for(i = -512; i < 512; i++)
        uiclp[i] = (i < 0 ? 0 : (i > 255 ? 255 : i));

    return 0;
}

static int roq_decode_frame(AVCodecContext *avctx,
                            void *data, int *data_size,
                            uint8_t *buf, int buf_size)
{
    RoqContext *s = avctx->priv_data;

    *data_size = 0;

    if (avctx->get_buffer(avctx, &s->current_frame)) {
        av_log(avctx, AV_LOG_ERROR, "  RoQ: get_buffer() failed\n");
        return -1;
    }
    s->y_stride = s->current_frame.linesize[0];
    s->c_stride = s->current_frame.linesize[1];

    s->buf = buf;
    s->size = buf_size;
    roqvideo_decode_frame(s);

    /* release the last frame if it is allocated */
    if (s->first_frame)
        s->first_frame = 0;
    else
        avctx->release_buffer(avctx, &s->last_frame);

    /* shuffle frames */
    s->last_frame = s->current_frame;

    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = s->current_frame;

    return buf_size;
}

static int roq_decode_end(AVCodecContext *avctx)
{
    RoqContext *s = avctx->priv_data;

    /* release the last frame */
    avctx->release_buffer(avctx, &s->last_frame);

    return 0;
}

AVCodec roq_decoder = {
    "roqvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_ROQ,
    sizeof(RoqContext),
    roq_decode_init,
    NULL,
    roq_decode_end,
    roq_decode_frame,
    CODEC_CAP_DR1,
};