PeerStreamer

/*

 * Copyright (C) 2003 the ffmpeg project

 *

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

 *

 * This library 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 this library; if not, write to the Free Software

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

 *

 */

/**

 * @file roqvideo.c

 * Id RoQ Video Decoder by Dr. Tim Ferguson

 * For more information about the Id RoQ format, visit:

 *   http://www.csse.monash.edu.au/~timf/

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "common.h"

#include "avcodec.h"

#include "dsputil.h"

typedef struct {

  unsigned char y0, y1, y2, y3, u, v;

} roq_cell;

typedef struct {

  int idx[4];

} roq_qcell;

static int uiclip[1024], *uiclp;  /* clipping table */

#define avg2(a,b) uiclp[(((int)(a)+(int)(b)+1)>>1)]

#define avg4(a,b,c,d) uiclp[(((int)(a)+(int)(b)+(int)(c)+(int)(d)+2)>>2)]

typedef struct RoqContext {

    AVCodecContext *avctx;

    DSPContext dsp;

    AVFrame last_frame;

    AVFrame current_frame;

    int first_frame;

    int y_stride;

    int c_stride;

    roq_cell cells[256];

    roq_qcell qcells[256];

    unsigned char *buf;

    int size;

} RoqContext;

#define RoQ_INFO              0x1001

#define RoQ_QUAD_CODEBOOK     0x1002

#define RoQ_QUAD_VQ           0x1011

#define RoQ_SOUND_MONO        0x1020

#define RoQ_SOUND_STEREO      0x1021

#define RoQ_ID_MOT              0x00

#define RoQ_ID_FCC              0x01

#define RoQ_ID_SLD              0x02

#define RoQ_ID_CCC              0x03

#define get_byte(in_buffer) *(in_buffer++)

#define get_word(in_buffer) ((unsigned short)(in_buffer += 2, \

  (in_buffer[-1] << 8 | in_buffer[-2])))

#define get_long(in_buffer) ((unsigned long)(in_buffer += 4, \

  (in_buffer[-1] << 24 | in_buffer[-2] << 16 | in_buffer[-3] << 8 | in_buffer[-4])))

static void apply_vector_2x2(RoqContext *ri, int x, int y, roq_cell *cell)

{

    unsigned char *yptr;

    yptr = ri->current_frame.data[0] + (y * ri->y_stride) + x;

    *yptr++ = cell->y0;

    *yptr++ = cell->y1;

    yptr += (ri->y_stride - 2);

    *yptr++ = cell->y2;

    *yptr++ = cell->y3;

    ri->current_frame.data[1][(y/2) * (ri->c_stride) + x/2] = cell->u;

    ri->current_frame.data[2][(y/2) * (ri->c_stride) + x/2] = cell->v;

}

static void apply_vector_4x4(RoqContext *ri, int x, int y, roq_cell *cell)

{

    unsigned long row_inc, c_row_inc;

    register unsigned char y0, y1, u, v;

    unsigned char *yptr, *uptr, *vptr;

    yptr = ri->current_frame.data[0] + (y * ri->y_stride) + x;

    uptr = ri->current_frame.data[1] + (y/2) * (ri->c_stride) + x/2;

    vptr = ri->current_frame.data[2] + (y/2) * (ri->c_stride) + x/2;

    row_inc = ri->y_stride - 4;

    c_row_inc = (ri->c_stride) - 2;

    *yptr++ = y0 = cell->y0; *uptr++ = u = cell->u; *vptr++ = v = cell->v;

    *yptr++ = y0;

    *yptr++ = y1 = cell->y1; *uptr++ = u; *vptr++ = v;

    *yptr++ = y1;

    yptr += row_inc;

    *yptr++ = y0;

    *yptr++ = y0;

    *yptr++ = y1;

    *yptr++ = y1;

    yptr += row_inc; uptr += c_row_inc; vptr += c_row_inc;

    *yptr++ = y0 = cell->y2; *uptr++ = u; *vptr++ = v;

    *yptr++ = y0;

    *yptr++ = y1 = cell->y3; *uptr++ = u; *vptr++ = v;

    *yptr++ = y1;

    yptr += row_inc;

    *yptr++ = y0;

    *yptr++ = y0;

    *yptr++ = y1;

    *yptr++ = y1;

}

static void apply_motion_4x4(RoqContext *ri, int x, int y, unsigned char mv,

    signed char mean_x, signed char mean_y)

{

    int i, hw, mx, my;

    unsigned char *pa, *pb;

    mx = x + 8 - (mv >> 4) - mean_x;

    my = y + 8 - (mv & 0xf) - mean_y;

    /* check MV against frame boundaries */

    if ((mx < 0) || (mx > ri->avctx->width - 4) ||

        (my < 0) || (my > ri->avctx->height - 4)) {

        av_log(ri->avctx, AV_LOG_ERROR, "motion vector out of bounds: MV = (%d, %d), boundaries = (0, 0, %d, %d)\n",

            mx, my, ri->avctx->width, ri->avctx->height);

        return;

    }

    pa = ri->current_frame.data[0] + (y * ri->y_stride) + x;

    pb = ri->last_frame.data[0] + (my * ri->y_stride) + mx;

    for(i = 0; i < 4; i++) {

        pa[0] = pb[0];

        pa[1] = pb[1];

        pa[2] = pb[2];

        pa[3] = pb[3];

        pa += ri->y_stride;

        pb += ri->y_stride;

    }

    hw = ri->y_stride/2;

    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(i = 0; i < 2; i++) {

        switch(((my & 0x01) << 1) | (mx & 0x01)) {

        case 0:

            pa[0] = pb[0];

            pa[1] = pb[1];

            pa[hw] = pb[hw];

            pa[hw+1] = pb[hw+1];

            break;

        case 1:

            pa[0] = avg2(pb[0], pb[1]);

            pa[1] = avg2(pb[1], pb[2]);

            pa[hw] = avg2(pb[hw], pb[hw+1]);

            pa[hw+1] = avg2(pb[hw+1], pb[hw+2]);

            break;

        case 2:

            pa[0] = avg2(pb[0], pb[hw]);

            pa[1] = avg2(pb[1], pb[hw+1]);

            pa[hw] = avg2(pb[hw], pb[hw*2]);

            pa[hw+1] = avg2(pb[hw+1], pb[(hw*2)+1]);

            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[hw] = avg4(pb[hw], pb[hw+1], pb[hw*2], pb[(hw*2)+1]);

            pa[hw+1] = avg4(pb[hw+1], pb[hw+2], pb[(hw*2)+1], pb[(hw*2)+1]);

            break;

        }

        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;

    }

}

static void apply_motion_8x8(RoqContext *ri, int x, int y,

    unsigned char mv, signed char mean_x, signed char mean_y)

{

    int mx, my, i, j, hw;

    unsigned char *pa, *pb;

    mx = x + 8 - (mv >> 4) - mean_x;

    my = y + 8 - (mv & 0xf) - mean_y;

    /* check MV against frame boundaries */

    if ((mx < 0) || (mx > ri->avctx->width - 8) ||

        (my < 0) || (my > ri->avctx->height - 8)) {

        av_log(ri->avctx, AV_LOG_ERROR, "motion vector out of bounds: MV = (%d, %d), boundaries = (0, 0, %d, %d)\n",

            mx, my, ri->avctx->width, ri->avctx->height);

        return;

    }

    pa = ri->current_frame.data[0] + (y * ri->y_stride) + x;

    pb = ri->last_frame.data[0] + (my * ri->y_stride) + mx;

    for(i = 0; i < 8; i++) {

        pa[0] = pb[0];

        pa[1] = pb[1];

        pa[2] = pb[2];

        pa[3] = pb[3];

        pa[4] = pb[4];

        pa[5] = pb[5];

        pa[6] = pb[6];

        pa[7] = pb[7];

        pa += ri->y_stride;

        pb += ri->y_stride;

    }

    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;

    }

}

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;

    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 */

    if (s->last_frame.data[0])

        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,

};