PeerStreamer

/*

 * VMware Screen Codec (VMnc) decoder

 * Copyright (c) 2006 Konstantin Shishkov

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file vmnc.c

 * VMware Screen Codec (VMnc) decoder

 * As Alex Beregszaszi discovered, this is effectively RFB data dump

 */

#include <stdio.h>

#include <stdlib.h>

#include "avcodec.h"

enum EncTypes {

    MAGIC_WMVd = 0x574D5664,

    MAGIC_WMVe,

    MAGIC_WMVf,

    MAGIC_WMVg,

    MAGIC_WMVh,

    MAGIC_WMVi,

    MAGIC_WMVj

};

enum HexTile_Flags {

    HT_RAW =  1, // tile is raw

    HT_BKG =  2, // background color is present

    HT_FG  =  4, // foreground color is present

    HT_SUB =  8, // subrects are present

    HT_CLR = 16  // each subrect has own color

};

/*

 * Decoder context

 */

typedef struct VmncContext {

    AVCodecContext *avctx;

    AVFrame pic;

    int bpp;

    int bpp2;

    int bigendian;

    uint8_t pal[768];

    int width, height;

    /* cursor data */

    int cur_w, cur_h;

    int cur_x, cur_y;

    int cur_hx, cur_hy;

    uint8_t* curbits, *curmask;

    uint8_t* screendta;

} VmncContext;

/* read pixel value from stream */

static av_always_inline int vmnc_get_pixel(uint8_t* buf, int bpp, int be) {

    switch(bpp * 2 + be) {

    case 2:

    case 3: return *buf;

    case 4: return AV_RL16(buf);

    case 5: return AV_RB16(buf);

    case 8: return AV_RL32(buf);

    case 9: return AV_RB32(buf);

    default: return 0;

    }

}

static void load_cursor(VmncContext *c, uint8_t *src)

{

    int i, j, p;

    const int bpp = c->bpp2;

    uint8_t  *dst8  = c->curbits;

    uint16_t *dst16 = (uint16_t*)c->curbits;

    uint32_t *dst32 = (uint32_t*)c->curbits;

    for(j = 0; j < c->cur_h; j++) {

        for(i = 0; i < c->cur_w; i++) {

            p = vmnc_get_pixel(src, bpp, c->bigendian);

            src += bpp;

            if(bpp == 1) *dst8++ = p;

            if(bpp == 2) *dst16++ = p;

            if(bpp == 4) *dst32++ = p;

        }

    }

    dst8 = c->curmask;

    dst16 = (uint16_t*)c->curmask;

    dst32 = (uint32_t*)c->curmask;

    for(j = 0; j < c->cur_h; j++) {

        for(i = 0; i < c->cur_w; i++) {

            p = vmnc_get_pixel(src, bpp, c->bigendian);

            src += bpp;

            if(bpp == 1) *dst8++ = p;

            if(bpp == 2) *dst16++ = p;

            if(bpp == 4) *dst32++ = p;

        }

    }

}

static void put_cursor(uint8_t *dst, int stride, VmncContext *c, int dx, int dy)

{

    int i, j;

    int w, h, x, y;

    w = c->cur_w;

    if(c->width < c->cur_x + c->cur_w) w = c->width - c->cur_x;

    h = c->cur_h;

    if(c->height < c->cur_y + c->cur_h) h = c->height - c->cur_y;

    x = c->cur_x;

    y = c->cur_y;

    if(x < 0) {

        w += x;

        x = 0;

    }

    if(y < 0) {

        h += y;

        y = 0;

    }

    if((w < 1) || (h < 1)) return;

    dst += x * c->bpp2 + y * stride;

    if(c->bpp2 == 1) {

        uint8_t* cd = c->curbits, *msk = c->curmask;

        for(j = 0; j < h; j++) {

            for(i = 0; i < w; i++)

                dst[i] = (dst[i] & cd[i]) ^ msk[i];

            msk += c->cur_w;

            cd += c->cur_w;

            dst += stride;

        }

    } else if(c->bpp2 == 2) {

        uint16_t* cd = (uint16_t*)c->curbits, *msk = (uint16_t*)c->curmask;

        uint16_t* dst2;

        for(j = 0; j < h; j++) {

            dst2 = (uint16_t*)dst;

            for(i = 0; i < w; i++)

                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];

            msk += c->cur_w;

            cd += c->cur_w;

            dst += stride;

        }

    } else if(c->bpp2 == 4) {

        uint32_t* cd = (uint32_t*)c->curbits, *msk = (uint32_t*)c->curmask;

        uint32_t* dst2;

        for(j = 0; j < h; j++) {

            dst2 = (uint32_t*)dst;

            for(i = 0; i < w; i++)

                dst2[i] = (dst2[i] & cd[i]) ^ msk[i];

            msk += c->cur_w;

            cd += c->cur_w;

            dst += stride;

        }

    }

}

/* fill rectangle with given color */

static av_always_inline void paint_rect(uint8_t *dst, int dx, int dy, int w, int h, int color, int bpp, int stride)

{

    int i, j;

    dst += dx * bpp + dy * stride;

    if(bpp == 1){

        for(j = 0; j < h; j++) {

            memset(dst, color, w);

            dst += stride;

        }

    }else if(bpp == 2){

        uint16_t* dst2;

        for(j = 0; j < h; j++) {

            dst2 = (uint16_t*)dst;

            for(i = 0; i < w; i++) {

                *dst2++ = color;

            }

            dst += stride;

        }

    }else if(bpp == 4){

        uint32_t* dst2;

        for(j = 0; j < h; j++) {

            dst2 = (uint32_t*)dst;

            for(i = 0; i < w; i++) {

                dst2[i] = color;

            }

            dst += stride;

        }

    }

}

static av_always_inline void paint_raw(uint8_t *dst, int w, int h, uint8_t* src, int bpp, int be, int stride)

{

    int i, j, p;

    for(j = 0; j < h; j++) {

        for(i = 0; i < w; i++) {

            p = vmnc_get_pixel(src, bpp, be);

            src += bpp;

            switch(bpp){

            case 1:

                dst[i] = p;

                break;

            case 2:

                ((uint16_t*)dst)[i] = p;

                break;

            case 4:

                ((uint32_t*)dst)[i] = p;

                break;

            }

        }

        dst += stride;

    }

}

static int decode_hextile(VmncContext *c, uint8_t* dst, uint8_t* src, int ssize, int w, int h, int stride)

{

    int i, j, k;

    int bg = 0, fg = 0, rects, color, flags, xy, wh;

    const int bpp = c->bpp2;

    uint8_t *dst2;

    int bw = 16, bh = 16;

    uint8_t *ssrc=src;

    for(j = 0; j < h; j += 16) {

        dst2 = dst;

        bw = 16;

        if(j + 16 > h) bh = h - j;

        for(i = 0; i < w; i += 16, dst2 += 16 * bpp) {

            if(src - ssrc >= ssize) {

                av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");

                return -1;

            }

            if(i + 16 > w) bw = w - i;

            flags = *src++;

            if(flags & HT_RAW) {

                if(src - ssrc > ssize - bw * bh * bpp) {

                    av_log(c->avctx, AV_LOG_ERROR, "Premature end of data!\n");

                    return -1;

                }

                paint_raw(dst2, bw, bh, src, bpp, c->bigendian, stride);

                src += bw * bh * bpp;

            } else {

                if(flags & HT_BKG) {

                    bg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;

                }

                if(flags & HT_FG) {

                    fg = vmnc_get_pixel(src, bpp, c->bigendian); src += bpp;

                }

                rects = 0;

                if(flags & HT_SUB)

                    rects = *src++;

                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, uint8_t *buf, int buf_size)

{

    VmncContext * const c = avctx->priv_data;

    uint8_t *outptr;

    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

};