mpv/cinepak.c

714 lines
20 KiB
C

/* ------------------------------------------------------------------------
* Radius Cinepak Video Decoder
*
* Dr. Tim Ferguson, 2001.
* For more details on the algorithm:
* http://www.csse.monash.edu.au/~timf/videocodec.html
*
* This is basically a vector quantiser with adaptive vector density. The
* frame is segmented into 4x4 pixel blocks, and each block is coded using
* either 1 or 4 vectors.
*
* There are still some issues with this code yet to be resolved. In
* particular with decoding in the strip boundaries.
* ------------------------------------------------------------------------ */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <math.h>
#include "config.h"
#define DBUG 0
#define MAX_STRIPS 32
/* ------------------------------------------------------------------------ */
typedef struct
{
unsigned char y0, y1, y2, y3;
char u, v;
unsigned long rgb0, rgb1, rgb2, rgb3; /* should be a union */
unsigned char r[4], g[4], b[4];
} cvid_codebook;
typedef struct {
cvid_codebook *v4_codebook[MAX_STRIPS];
cvid_codebook *v1_codebook[MAX_STRIPS];
unsigned long strip_num;
} cinepak_info;
/* ------------------------------------------------------------------------ */
static unsigned char *in_buffer, uiclip[1024], *uiclp = NULL;
#define SCALEBITS 16
#define ONE_HALF ((long) 1 << (SCALEBITS-1))
#define FIX(x) ((long) ((x) * (1L<<SCALEBITS) + 0.5))
static long CU_Y_tab[256], CV_Y_tab[256], CU_Cb_tab[256], CV_Cb_tab[256],
CU_Cr_tab[256], CV_Cr_tab[256];
#define get_byte() *(in_buffer++)
#define skip_byte() in_buffer++
#define get_word() ((unsigned short)(in_buffer += 2, \
(in_buffer[-2] << 8 | in_buffer[-1])))
#define get_long() ((unsigned long)(in_buffer += 4, \
(in_buffer[-4] << 24 | in_buffer[-3] << 16 | in_buffer[-2] << 8 | in_buffer[-1])))
/* ---------------------------------------------------------------------- */
static inline void read_codebook_yuy2(cvid_codebook *c, int mode)
{
unsigned char y0, y1, y2, y3, u, v;
int y_uv;
if(mode) /* black and white */
{
c->y0 = get_byte();
c->y1 = get_byte();
c->y2 = get_byte();
c->y3 = get_byte();
c->u = c->v = 128;
}
else /* colour */
{
y0 = get_byte(); /* luma */
y1 = get_byte();
y2 = get_byte();
y3 = get_byte();
u = 128+get_byte(); /* chroma */
v = 128+get_byte();
/* YUV * inv(CinYUV)
* | Y | | 1 -0.0655 0.0110 | | CY |
* | Cb | = | 0 1.1656 -0.0062 | | CU |
* | Cr | | 0 0.0467 1.4187 | | CV |
*/
y_uv = (int)((CU_Y_tab[u] + CV_Y_tab[v]) >> SCALEBITS);
c->y0 = uiclp[y0 + y_uv];
c->y1 = uiclp[y1 + y_uv];
c->y2 = uiclp[y2 + y_uv];
c->y3 = uiclp[y3 + y_uv];
c->u = uiclp[(int)((CU_Cb_tab[u] + CV_Cb_tab[v]) >> SCALEBITS)];
c->v = uiclp[(int)((CU_Cr_tab[u] + CV_Cr_tab[v]) >> SCALEBITS)];
}
}
//#define PACK_YUV(cb,y0,y1,u,v) ((cb->y0<<24)|(((unsigned char)cb->u)<<16)|(cb->y1<<8)|(((unsigned char)cb->v)))
#define PACK_YUV(cb,y0,y1,u,v) ((((unsigned char)cb->v)<<24)|(cb->y1<<16)|(((unsigned char)cb->u)<<8)|(cb->y0))
#define TO_YUY2_U0(cb) PACK_YUV(cb,y0,y0,u,v)
#define TO_YUY2_U1(cb) PACK_YUV(cb,y1,y1,u,v)
#define TO_YUY2_L0(cb) PACK_YUV(cb,y2,y2,u,v)
#define TO_YUY2_L1(cb) PACK_YUV(cb,y3,y3,u,v)
#define TO_YUY2_U(cb) PACK_YUV(cb,y0,y1,u,v)
#define TO_YUY2_L(cb) PACK_YUV(cb,y2,y3,u,v)
/* ------------------------------------------------------------------------ */
inline void cvid_v1_yuy2(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb)
{
unsigned long *vptr = (unsigned long *)frm, rgb;
int row_inc = stride/4;
vptr[0] = TO_YUY2_U0(cb);
vptr[1] = TO_YUY2_U1(cb);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_U0(cb);
vptr[1] = TO_YUY2_U1(cb);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_L0(cb);
vptr[1] = TO_YUY2_L1(cb);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_L0(cb);
vptr[1] = TO_YUY2_L1(cb);
}
/* ------------------------------------------------------------------------ */
inline void cvid_v4_yuy2(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb0,
cvid_codebook *cb1, cvid_codebook *cb2, cvid_codebook *cb3)
{
unsigned long *vptr = (unsigned long *)frm;
int row_inc = stride/4;
vptr[0] = TO_YUY2_U(cb0);
vptr[1] = TO_YUY2_U(cb1);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_L(cb0);
vptr[1] = TO_YUY2_L(cb1);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_U(cb2);
vptr[1] = TO_YUY2_U(cb3);
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = TO_YUY2_L(cb2);
vptr[1] = TO_YUY2_L(cb3);
}
/* ---------------------------------------------------------------------- */
static inline void read_codebook_32(cvid_codebook *c, int mode)
{
int uvr, uvg, uvb;
if(mode) /* black and white */
{
c->y0 = get_byte();
c->y1 = get_byte();
c->y2 = get_byte();
c->y3 = get_byte();
c->u = c->v = 0;
c->rgb0 = (c->y0 << 16) | (c->y0 << 8) | c->y0;
c->rgb1 = (c->y1 << 16) | (c->y1 << 8) | c->y1;
c->rgb2 = (c->y2 << 16) | (c->y2 << 8) | c->y2;
c->rgb3 = (c->y3 << 16) | (c->y3 << 8) | c->y3;
}
else /* colour */
{
c->y0 = get_byte(); /* luma */
c->y1 = get_byte();
c->y2 = get_byte();
c->y3 = get_byte();
c->u = get_byte(); /* chroma */
c->v = get_byte();
uvr = c->v << 1;
uvg = -((c->u+1) >> 1) - c->v;
uvb = c->u << 1;
c->rgb0 = (uiclp[c->y0 + uvr] << 16) | (uiclp[c->y0 + uvg] << 8) | uiclp[c->y0 + uvb];
c->rgb1 = (uiclp[c->y1 + uvr] << 16) | (uiclp[c->y1 + uvg] << 8) | uiclp[c->y1 + uvb];
c->rgb2 = (uiclp[c->y2 + uvr] << 16) | (uiclp[c->y2 + uvg] << 8) | uiclp[c->y2 + uvb];
c->rgb3 = (uiclp[c->y3 + uvr] << 16) | (uiclp[c->y3 + uvg] << 8) | uiclp[c->y3 + uvb];
}
}
/* ------------------------------------------------------------------------ */
inline void cvid_v1_32(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb)
{
unsigned long *vptr = (unsigned long *)frm, rgb;
int row_inc = stride/4;
vptr[0] = rgb = cb->rgb0; vptr[1] = rgb;
vptr[2] = rgb = cb->rgb1; vptr[3] = rgb;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = rgb = cb->rgb0; vptr[1] = rgb;
vptr[2] = rgb = cb->rgb1; vptr[3] = rgb;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = rgb = cb->rgb2; vptr[1] = rgb;
vptr[2] = rgb = cb->rgb3; vptr[3] = rgb;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = rgb = cb->rgb2; vptr[1] = rgb;
vptr[2] = rgb = cb->rgb3; vptr[3] = rgb;
}
/* ------------------------------------------------------------------------ */
inline void cvid_v4_32(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb0,
cvid_codebook *cb1, cvid_codebook *cb2, cvid_codebook *cb3)
{
unsigned long *vptr = (unsigned long *)frm;
int row_inc = stride/4;
vptr[0] = cb0->rgb0;
vptr[1] = cb0->rgb1;
vptr[2] = cb1->rgb0;
vptr[3] = cb1->rgb1;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = cb0->rgb2;
vptr[1] = cb0->rgb3;
vptr[2] = cb1->rgb2;
vptr[3] = cb1->rgb3;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = cb2->rgb0;
vptr[1] = cb2->rgb1;
vptr[2] = cb3->rgb0;
vptr[3] = cb3->rgb1;
vptr += row_inc; if(vptr > (unsigned long *)end) return;
vptr[0] = cb2->rgb2;
vptr[1] = cb2->rgb3;
vptr[2] = cb3->rgb2;
vptr[3] = cb3->rgb3;
}
/* ---------------------------------------------------------------------- */
static inline void read_codebook_24(cvid_codebook *c, int mode)
{
int uvr, uvg, uvb;
if(mode) /* black and white */
{
c->y0 = get_byte();
c->y1 = get_byte();
c->y2 = get_byte();
c->y3 = get_byte();
c->u = c->v = 0;
c->r[0] = c->g[0] = c->b[0] = c->y0;
c->r[1] = c->g[1] = c->b[1] = c->y1;
c->r[2] = c->g[2] = c->b[2] = c->y2;
c->r[3] = c->g[3] = c->b[3] = c->y3;
}
else /* colour */
{
c->y0 = get_byte(); /* luma */
c->y1 = get_byte();
c->y2 = get_byte();
c->y3 = get_byte();
c->u = get_byte(); /* chroma */
c->v = get_byte();
uvr = c->v << 1;
uvg = -((c->u+1) >> 1) - c->v;
uvb = c->u << 1;
c->r[0] = uiclp[c->y0 + uvr]; c->g[0] = uiclp[c->y0 + uvg]; c->b[0] = uiclp[c->y0 + uvb];
c->r[1] = uiclp[c->y1 + uvr]; c->g[1] = uiclp[c->y1 + uvg]; c->b[1] = uiclp[c->y1 + uvb];
c->r[2] = uiclp[c->y2 + uvr]; c->g[2] = uiclp[c->y2 + uvg]; c->b[2] = uiclp[c->y2 + uvb];
c->r[3] = uiclp[c->y3 + uvr]; c->g[3] = uiclp[c->y3 + uvg]; c->b[3] = uiclp[c->y3 + uvb];
}
}
/* ------------------------------------------------------------------------ */
void cvid_v1_24(unsigned char *vptr, unsigned char *end, int stride, cvid_codebook *cb)
{
unsigned char r, g, b;
int row_inc = stride-4*3;
*vptr++ = b = cb->b[0]; *vptr++ = g = cb->g[0]; *vptr++ = r = cb->r[0];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
*vptr++ = b = cb->b[1]; *vptr++ = g = cb->g[1]; *vptr++ = r = cb->r[1];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
vptr += row_inc; if(vptr > end) return;
*vptr++ = b = cb->b[0]; *vptr++ = g = cb->g[0]; *vptr++ = r = cb->r[0];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
*vptr++ = b = cb->b[1]; *vptr++ = g = cb->g[1]; *vptr++ = r = cb->r[1];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
vptr += row_inc; if(vptr > end) return;
*vptr++ = b = cb->b[2]; *vptr++ = g = cb->g[2]; *vptr++ = r = cb->r[2];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
*vptr++ = b = cb->b[3]; *vptr++ = g = cb->g[3]; *vptr++ = r = cb->r[3];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
vptr += row_inc; if(vptr > end) return;
*vptr++ = b = cb->b[2]; *vptr++ = g = cb->g[2]; *vptr++ = r = cb->r[2];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
*vptr++ = b = cb->b[3]; *vptr++ = g = cb->g[3]; *vptr++ = r = cb->r[3];
*vptr++ = b; *vptr++ = g; *vptr++ = r;
}
/* ------------------------------------------------------------------------ */
void cvid_v4_24(unsigned char *vptr, unsigned char *end, int stride, cvid_codebook *cb0,
cvid_codebook *cb1, cvid_codebook *cb2, cvid_codebook *cb3)
{
int row_inc = stride-4*3;
*vptr++ = cb0->b[0]; *vptr++ = cb0->g[0]; *vptr++ = cb0->r[0];
*vptr++ = cb0->b[1]; *vptr++ = cb0->g[1]; *vptr++ = cb0->r[1];
*vptr++ = cb1->b[0]; *vptr++ = cb1->g[0]; *vptr++ = cb1->r[0];
*vptr++ = cb1->b[1]; *vptr++ = cb1->g[1]; *vptr++ = cb1->r[1];
vptr += row_inc; if(vptr > end) return;
*vptr++ = cb0->b[2]; *vptr++ = cb0->g[2]; *vptr++ = cb0->r[2];
*vptr++ = cb0->b[3]; *vptr++ = cb0->g[3]; *vptr++ = cb0->r[3];
*vptr++ = cb1->b[2]; *vptr++ = cb1->g[2]; *vptr++ = cb1->r[2];
*vptr++ = cb1->b[3]; *vptr++ = cb1->g[3]; *vptr++ = cb1->r[3];
vptr += row_inc; if(vptr > end) return;
*vptr++ = cb2->b[0]; *vptr++ = cb2->g[0]; *vptr++ = cb2->r[0];
*vptr++ = cb2->b[1]; *vptr++ = cb2->g[1]; *vptr++ = cb2->r[1];
*vptr++ = cb3->b[0]; *vptr++ = cb3->g[0]; *vptr++ = cb3->r[0];
*vptr++ = cb3->b[1]; *vptr++ = cb3->g[1]; *vptr++ = cb3->r[1];
vptr += row_inc; if(vptr > end) return;
*vptr++ = cb2->b[2]; *vptr++ = cb2->g[2]; *vptr++ = cb2->r[2];
*vptr++ = cb2->b[3]; *vptr++ = cb2->g[3]; *vptr++ = cb2->r[3];
*vptr++ = cb3->b[2]; *vptr++ = cb3->g[2]; *vptr++ = cb3->r[2];
*vptr++ = cb3->b[3]; *vptr++ = cb3->g[3]; *vptr++ = cb3->r[3];
}
/* ------------------------------------------------------------------------
* Call this function once at the start of the sequence and save the
* returned context for calls to decode_cinepak().
*/
void *decode_cinepak_init(void)
{
cinepak_info *cvinfo;
int i, x;
if((cvinfo = calloc(sizeof(cinepak_info), 1)) == NULL) return NULL;
cvinfo->strip_num = 0;
if(uiclp == NULL)
{
uiclp = uiclip+512;
for(i = -512; i < 512; i++)
uiclp[i] = (i < 0 ? 0 : (i > 255 ? 255 : i));
}
for(i = 0, x = -128; i < 256; i++, x++)
{
CU_Y_tab[i] = (-FIX(0.0655)) * x;
CV_Y_tab[i] = (FIX(0.0110)) * x + ONE_HALF;
CU_Cb_tab[i] = (FIX(1.1656)) * x;
CV_Cb_tab[i] = (-FIX(0.0062)) * x + ONE_HALF + FIX(128);
CU_Cr_tab[i] = (FIX(0.0467)) * x;
CV_Cr_tab[i] = (FIX(1.4187)) * x + ONE_HALF + FIX(128);
}
return (void *)cvinfo;
}
/* ------------------------------------------------------------------------
* This function decodes a buffer containing a Cinepak encoded frame.
*
* context - the context created by decode_cinepak_init().
* buf - the input buffer to be decoded
* size - the size of the input buffer
* frame - the output frame buffer (24 or 32 bit per pixel)
* width - the width of the output frame
* height - the height of the output frame
* bit_per_pixel - the number of bits per pixel allocated to the output
* frame (only 24 or 32 bpp are supported)
*/
void decode_cinepak(void *context, unsigned char *buf, int size, unsigned char *frame, int width, int height, int bit_per_pixel, int stride_)
{
cinepak_info *cvinfo = (cinepak_info *)context;
cvid_codebook *v4_codebook, *v1_codebook, *codebook = NULL;
unsigned long x, y, y_bottom, frame_flags, strips, cv_width, cv_height, cnum,
strip_id, chunk_id, x0, y0, x1, y1, ci, flag, mask;
long len, top_size, chunk_size;
unsigned char *frm_ptr, *frm_end;
int i, cur_strip, d0, d1, d2, d3, frm_stride, bpp = 3;
int modulo;
void (*read_codebook)(cvid_codebook *c, int mode) = read_codebook_24;
void (*cvid_v1)(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb) = cvid_v1_24;
void (*cvid_v4)(unsigned char *frm, unsigned char *end, int stride, cvid_codebook *cb0,
cvid_codebook *cb1, cvid_codebook *cb2, cvid_codebook *cb3) = cvid_v4_24;
x = y = 0;
y_bottom = 0;
in_buffer = buf;
frame_flags = get_byte();
len = get_byte() << 16;
len |= get_byte() << 8;
len |= get_byte();
switch(bit_per_pixel)
{
case 16:
bpp = 2;
read_codebook = read_codebook_yuy2;
cvid_v1 = cvid_v1_yuy2;
cvid_v4 = cvid_v4_yuy2;
break;
case 24:
bpp = 3;
read_codebook = read_codebook_24;
cvid_v1 = cvid_v1_24;
cvid_v4 = cvid_v4_24;
break;
case 32:
bpp = 4;
read_codebook = read_codebook_32;
cvid_v1 = cvid_v1_32;
cvid_v4 = cvid_v4_32;
break;
}
frm_stride = stride_ ? stride_ : width * bpp;
frm_ptr = frame;
frm_end = frm_ptr + width * height * bpp;
if(len != size)
{
if(len & 0x01) len++; /* AVIs tend to have a size mismatch */
if(len != size)
{
printf("CVID: corruption %d (QT/AVI) != %ld (CV)\n", size, len);
// return;
}
}
cv_width = get_word();
cv_height = get_word();
strips = get_word();
if(strips > cvinfo->strip_num)
{
if(strips >= MAX_STRIPS)
{
printf("CVID: strip overflow (more than %d)\n", MAX_STRIPS);
return;
}
for(i = cvinfo->strip_num; i < strips; i++)
{
if((cvinfo->v4_codebook[i] = (cvid_codebook *)calloc(sizeof(cvid_codebook), 260)) == NULL)
{
printf("CVID: codebook v4 alloc err\n");
return;
}
if((cvinfo->v1_codebook[i] = (cvid_codebook *)calloc(sizeof(cvid_codebook), 260)) == NULL)
{
printf("CVID: codebook v1 alloc err\n");
return;
}
}
}
cvinfo->strip_num = strips;
#if DBUG
printf("CVID: <%ld,%ld> strips %ld\n", cv_width, cv_height, strips);
#endif
for(cur_strip = 0; cur_strip < strips; cur_strip++)
{
v4_codebook = cvinfo->v4_codebook[cur_strip];
v1_codebook = cvinfo->v1_codebook[cur_strip];
if((cur_strip > 0) && (!(frame_flags & 0x01)))
{
memcpy(cvinfo->v4_codebook[cur_strip], cvinfo->v4_codebook[cur_strip-1], 260 * sizeof(cvid_codebook));
memcpy(cvinfo->v1_codebook[cur_strip], cvinfo->v1_codebook[cur_strip-1], 260 * sizeof(cvid_codebook));
}
strip_id = get_word(); /* 1000 = key strip, 1100 = iter strip */
top_size = get_word();
y0 = get_word(); /* FIXME: most of these are ignored at the moment */
x0 = get_word();
y1 = get_word();
x1 = get_word();
y_bottom += y1;
top_size -= 12;
x = 0;
if(x1 != width)
printf("CVID: Warning x1 (%ld) != width (%d)\n", x1, width);
x1 = width;
#if DBUG
printf(" %d) %04lx %04ld <%ld,%ld> <%ld,%ld> yt %ld %d\n",
cur_strip, strip_id, top_size, x0, y0, x1, y1, y_bottom);
#endif
while(top_size > 0)
{
chunk_id = get_word();
chunk_size = get_word();
#if DBUG
printf(" %04lx %04ld\n", chunk_id, chunk_size);
#endif
top_size -= chunk_size;
chunk_size -= 4;
switch(chunk_id)
{
/* -------------------- Codebook Entries -------------------- */
case 0x2000:
case 0x2200:
modulo = chunk_size % 6;
codebook = (chunk_id == 0x2200 ? v1_codebook : v4_codebook);
cnum = (chunk_size - modulo) / 6;
for(i = 0; i < cnum; i++) read_codebook(codebook+i, 0);
while (modulo--)
get_byte();
break;
case 0x2400:
case 0x2600: /* 8 bit per pixel */
codebook = (chunk_id == 0x2600 ? v1_codebook : v4_codebook);
cnum = chunk_size/4;
for(i = 0; i < cnum; i++) read_codebook(codebook+i, 1);
break;
case 0x2100:
case 0x2300:
codebook = (chunk_id == 0x2300 ? v1_codebook : v4_codebook);
ci = 0;
while(chunk_size > 3)
{
flag = get_long();
chunk_size -= 4;
for(i = 0; i < 32; i++)
{
if(flag & 0x80000000)
{
chunk_size -= 6;
read_codebook(codebook+ci, 0);
}
ci++;
flag <<= 1;
}
}
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
case 0x2500:
case 0x2700: /* 8 bit per pixel */
codebook = (chunk_id == 0x2700 ? v1_codebook : v4_codebook);
ci = 0;
while(chunk_size > 0)
{
flag = get_long();
chunk_size -= 4;
for(i = 0; i < 32; i++)
{
if(flag & 0x80000000)
{
chunk_size -= 4;
read_codebook(codebook+ci, 1);
}
ci++;
flag <<= 1;
}
}
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
/* -------------------- Frame -------------------- */
case 0x3000:
while((chunk_size > 0) && (y < y_bottom))
{
flag = get_long();
chunk_size -= 4;
for(i = 0; i < 32; i++)
{
if(y >= y_bottom) break;
if(flag & 0x80000000) /* 4 bytes per block */
{
d0 = get_byte();
d1 = get_byte();
d2 = get_byte();
d3 = get_byte();
chunk_size -= 4;
cvid_v4(frm_ptr + (y * frm_stride + x * bpp), frm_end, frm_stride, v4_codebook+d0, v4_codebook+d1, v4_codebook+d2, v4_codebook+d3);
}
else /* 1 byte per block */
{
cvid_v1(frm_ptr + (y * frm_stride + x * bpp), frm_end, frm_stride, v1_codebook + get_byte());
chunk_size--;
}
x += 4;
if(x >= width)
{
x = 0;
y += 4;
}
flag <<= 1;
}
}
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
case 0x3100:
while((chunk_size > 0) && (y < y_bottom))
{
/* ---- flag bits: 0 = SKIP, 10 = V1, 11 = V4 ---- */
flag = (unsigned long)get_long();
chunk_size -= 4;
mask = 0x80000000;
while((mask) && (y < y_bottom))
{
if(flag & mask)
{
if(mask == 1)
{
if(chunk_size < 0) break;
flag = (unsigned long)get_long();
chunk_size -= 4;
mask = 0x80000000;
}
else mask >>= 1;
if(flag & mask) /* V4 */
{
d0 = get_byte();
d1 = get_byte();
d2 = get_byte();
d3 = get_byte();
chunk_size -= 4;
cvid_v4(frm_ptr + (y * frm_stride + x * bpp), frm_end, frm_stride, v4_codebook+d0, v4_codebook+d1, v4_codebook+d2, v4_codebook+d3);
}
else /* V1 */
{
chunk_size--;
cvid_v1(frm_ptr + (y * frm_stride + x * bpp), frm_end, frm_stride, v1_codebook + get_byte());
}
} /* else SKIP */
mask >>= 1;
x += 4;
if(x >= width)
{
x = 0;
y += 4;
}
}
}
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
case 0x3200: /* each byte is a V1 codebook */
while((chunk_size > 0) && (y < y_bottom))
{
cvid_v1(frm_ptr + (y * frm_stride + x * bpp), frm_end, frm_stride, v1_codebook + get_byte());
chunk_size--;
x += 4;
if(x >= width)
{
x = 0;
y += 4;
}
}
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
default:
printf("CVID: unknown chunk_id %08lx\n", chunk_id);
while(chunk_size > 0) { skip_byte(); chunk_size--; }
break;
}
}
}
if(len != size)
{
if(len & 0x01) len++; /* AVIs tend to have a size mismatch */
if(len != size)
{
long xlen;
skip_byte();
xlen = get_byte() << 16;
xlen |= get_byte() << 8;
xlen |= get_byte(); /* Read Len */
printf("CVID: END INFO chunk size %d cvid size1 %ld cvid size2 %ld\n", size, len, xlen);
}
}
}