vmnc.c

mediastreamer2是开源的网络传输媒体流的库

                color = !!(flags & HT_CLR);

                paint_rect(dst2, 0, 0, bw, bh, bg, bpp, stride);

                if(src - ssrc > ssize - rects * (color * bpp + 2)) {
                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");
                    return -1;
                }
                for(k = 0; k < rects; k++) {
                    if(color) {
                        fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;
                    }
                    xy = *src++;
                    wh = *src++;
                    paint_rect(dst2, xy >> 4, xy & 0xF, (wh>>4)+1, (wh & 0xF)+1, fg, bpp, stride);
                }
            }
        }
        dst += stride * 16;
    }
    return src - ssrc;
}

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
{
    VmncContext * const c = avctx->priv_data;
    uint8_t *outptr;
    const uint8_t *src = buf;
    int dx, dy, w, h, depth, enc, chunks, res, size_left;

    c->pic.reference = 1;
    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
    if(avctx->reget_buffer(avctx, &c->pic) < 0){
        av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
        return -1;
    }

    c->pic.key_frame = 0;
    c->pic.pict_type = FF_P_TYPE;

    //restore screen after cursor
    if(c->screendta) {
        int i;
        w = c->cur_w;
        if(c->width < c->cur_x + w) w = c->width - c->cur_x;
        h = c->cur_h;
        if(c->height < c->cur_y + h) h = c->height - c->cur_y;
        dx = c->cur_x;
        if(dx < 0) {
            w += dx;
            dx = 0;
        }
        dy = c->cur_y;
        if(dy < 0) {
            h += dy;
            dy = 0;
        }
        if((w > 0) && (h > 0)) {
            outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
            for(i = 0; i < h; i++) {
                memcpy(outptr, c->screendta + i * c->cur_w * c->bpp2, w * c->bpp2);
                outptr += c->pic.linesize[0];
            }
        }
    }
    src += 2;
    chunks = AV_RB16(src); src += 2;
    while(chunks--) {
        dx = AV_RB16(src); src += 2;
        dy = AV_RB16(src); src += 2;
        w  = AV_RB16(src); src += 2;
        h  = AV_RB16(src); src += 2;
        enc = AV_RB32(src); src += 4;
        outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
        size_left = buf_size - (src - buf);
        switch(enc) {
        case MAGIC_WMVd: // cursor
            if(size_left < 2 + w * h * c->bpp2 * 2) {
                av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", 2 + w * h * c->bpp2 * 2, size_left);
                return -1;
            }
            src += 2;
            c->cur_w = w;
            c->cur_h = h;
            c->cur_hx = dx;
            c->cur_hy = dy;
            if((c->cur_hx > c->cur_w) || (c->cur_hy > c->cur_h)) {
                av_log(avctx, AV_LOG_ERROR, "Cursor hot spot is not in image: %ix%i of %ix%i cursor size\n", c->cur_hx, c->cur_hy, c->cur_w, c->cur_h);
                c->cur_hx = c->cur_hy = 0;
            }
            c->curbits = av_realloc(c->curbits, c->cur_w * c->cur_h * c->bpp2);
            c->curmask = av_realloc(c->curmask, c->cur_w * c->cur_h * c->bpp2);
            c->screendta = av_realloc(c->screendta, c->cur_w * c->cur_h * c->bpp2);
            load_cursor(c, src);
            src += w * h * c->bpp2 * 2;
            break;
        case MAGIC_WMVe: // unknown
            src += 2;
            break;
        case MAGIC_WMVf: // update cursor position
            c->cur_x = dx - c->cur_hx;
            c->cur_y = dy - c->cur_hy;
            break;
        case MAGIC_WMVg: // unknown
            src += 10;
            break;
        case MAGIC_WMVh: // unknown
            src += 4;
            break;
        case MAGIC_WMVi: // ServerInitialization struct
            c->pic.key_frame = 1;
            c->pic.pict_type = FF_I_TYPE;
            depth = *src++;
            if(depth != c->bpp) {
                av_log(avctx, AV_LOG_INFO, "Depth mismatch. Container %i bpp, Frame data: %i bpp\n", c->bpp, depth);
            }
            src++;
            c->bigendian = *src++;
            if(c->bigendian & (~1)) {
                av_log(avctx, AV_LOG_INFO, "Invalid header: bigendian flag = %i\n", c->bigendian);
                return -1;
            }
            //skip the rest of pixel format data
            src += 13;
            break;
        case MAGIC_WMVj: // unknown
            src += 2;
            break;
        case 0x00000000: // raw rectangle data
            if((dx + w > c->width) || (dy + h > c->height)) {
                av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
                return -1;
            }
            if(size_left < w * h * c->bpp2) {
                av_log(avctx, AV_LOG_ERROR, "Premature end of data! (need %i got %i)\n", w * h * c->bpp2, size_left);
                return -1;
            }
            paint_raw(outptr, w, h, src, c->bpp2, c->bigendian, c->pic.linesize[0]);
            src += w * h * c->bpp2;
            break;
        case 0x00000005: // HexTile encoded rectangle
            if((dx + w > c->width) || (dy + h > c->height)) {
                av_log(avctx, AV_LOG_ERROR, "Incorrect frame size: %ix%i+%ix%i of %ix%i\n", w, h, dx, dy, c->width, c->height);
                return -1;
            }
            res = decode_hextile(c, outptr, src, size_left, w, h, c->pic.linesize[0]);
            if(res < 0)
                return -1;
            src += res;
            break;
        default:
            av_log(avctx, AV_LOG_ERROR, "Unsupported block type 0x%08X\n", enc);
            chunks = 0; // leave chunks decoding loop
        }
    }
    if(c->screendta){
        int i;
        //save screen data before painting cursor
        w = c->cur_w;
        if(c->width < c->cur_x + w) w = c->width - c->cur_x;
        h = c->cur_h;
        if(c->height < c->cur_y + h) h = c->height - c->cur_y;
        dx = c->cur_x;
        if(dx < 0) {
            w += dx;
            dx = 0;
        }
        dy = c->cur_y;
        if(dy < 0) {
            h += dy;
            dy = 0;
        }
        if((w > 0) && (h > 0)) {
            outptr = c->pic.data[0] + dx * c->bpp2 + dy * c->pic.linesize[0];
            for(i = 0; i < h; i++) {
                memcpy(c->screendta + i * c->cur_w * c->bpp2, outptr, w * c->bpp2);
                outptr += c->pic.linesize[0];
            }
            outptr = c->pic.data[0];
            put_cursor(outptr, c->pic.linesize[0], c, c->cur_x, c->cur_y);
        }
    }
    *data_size = sizeof(AVFrame);
    *(AVFrame*)data = c->pic;

    /* always report that the buffer was completely consumed */
    return buf_size;
}



/*
 *
 * Init VMnc decoder
 *
 */
static int decode_init(AVCodecContext *avctx)
{
    VmncContext * const c = avctx->priv_data;

    c->avctx = avctx;

    c->pic.data[0] = NULL;
    c->width = avctx->width;
    c->height = avctx->height;

    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
        return 1;
    }
    c->bpp = avctx->bits_per_sample;
    c->bpp2 = c->bpp/8;

    switch(c->bpp){
    case 8:
        avctx->pix_fmt = PIX_FMT_PAL8;
        break;
    case 16:
        avctx->pix_fmt = PIX_FMT_RGB555;
        break;
    case 32:
        avctx->pix_fmt = PIX_FMT_RGB32;
        break;
    default:
        av_log(avctx, AV_LOG_ERROR, "Unsupported bitdepth %i\n", c->bpp);
    }

    return 0;
}



/*
 *
 * Uninit VMnc decoder
 *
 */
static int decode_end(AVCodecContext *avctx)
{
    VmncContext * const c = avctx->priv_data;

    if (c->pic.data[0])
        avctx->release_buffer(avctx, &c->pic);

    av_free(c->curbits);
    av_free(c->curmask);
    av_free(c->screendta);
    return 0;
}

AVCodec vmnc_decoder = {
    "VMware video",
    CODEC_TYPE_VIDEO,
    CODEC_ID_VMNC,
    sizeof(VmncContext),
    decode_init,
    NULL,
    decode_end,
    decode_frame
};