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ffmpeg/libavcodec/xan.c
Mike Melanson 0f371e3e2a final word on RGBA byte order 
Originally committed as revision 2268 to svn://svn.ffmpeg.org/ffmpeg/trunk
2003-09-13 02:31:03 +00:00

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/*
* Wing Commander/Xan Video Decoder
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/**
* @file xan.c
* Xan video decoder for Wing Commander III & IV computer games
* by Mario Brito (mbrito@student.dei.uc.pt)
* and Mike Melanson (melanson@pcisys.net)
*
* The xan_wc3 decoder outputs the following colorspaces natively:
* PAL8 (default), RGB555, RGB565, RGB24, BGR24, RGBA32, YUV444P
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "common.h"
#include "avcodec.h"
#include "dsputil.h"
#define PALETTE_COUNT 256
#define PALETTE_CONTROL_SIZE ((256 * 3) + 1)
typedef struct XanContext {
AVCodecContext *avctx;
DSPContext dsp;
AVFrame last_frame;
AVFrame current_frame;
unsigned char *buf;
int size;
unsigned char palette[PALETTE_COUNT * 4];
/* scratch space */
unsigned char *buffer1;
unsigned char *buffer2;
} XanContext;
#define BE_16(x) ((((uint8_t*)(x))[0] << 8) | ((uint8_t*)(x))[1])
#define LE_16(x) ((((uint8_t*)(x))[1] << 8) | ((uint8_t*)(x))[0])
#define LE_32(x) ((((uint8_t*)(x))[3] << 24) | \
(((uint8_t*)(x))[2] << 16) | \
(((uint8_t*)(x))[1] << 8) | \
((uint8_t*)(x))[0])
/* RGB -> YUV conversion stuff */
#define SCALEFACTOR 65536
#define CENTERSAMPLE 128
#define COMPUTE_Y(r, g, b) \
(unsigned char) \
((y_r_table[r] + y_g_table[g] + y_b_table[b]) / SCALEFACTOR)
#define COMPUTE_U(r, g, b) \
(unsigned char) \
((u_r_table[r] + u_g_table[g] + u_b_table[b]) / SCALEFACTOR + CENTERSAMPLE)
#define COMPUTE_V(r, g, b) \
(unsigned char) \
((v_r_table[r] + v_g_table[g] + v_b_table[b]) / SCALEFACTOR + CENTERSAMPLE)
#define Y_R (SCALEFACTOR * 0.29900)
#define Y_G (SCALEFACTOR * 0.58700)
#define Y_B (SCALEFACTOR * 0.11400)
#define U_R (SCALEFACTOR * -0.16874)
#define U_G (SCALEFACTOR * -0.33126)
#define U_B (SCALEFACTOR * 0.50000)
#define V_R (SCALEFACTOR * 0.50000)
#define V_G (SCALEFACTOR * -0.41869)
#define V_B (SCALEFACTOR * -0.08131)
/*
* Precalculate all of the YUV tables since it requires fewer than
* 10 kilobytes to store them.
*/
static int y_r_table[256];
static int y_g_table[256];
static int y_b_table[256];
static int u_r_table[256];
static int u_g_table[256];
static int u_b_table[256];
static int v_r_table[256];
static int v_g_table[256];
static int v_b_table[256];
static int xan_decode_init(AVCodecContext *avctx)
{
XanContext *s = avctx->priv_data;
int i;
s->avctx = avctx;
if ((avctx->codec->id == CODEC_ID_XAN_WC3) &&
(s->avctx->extradata_size != sizeof(AVPaletteControl))) {
printf (" WC3 Xan video: expected extradata_size of %d\n",
sizeof(AVPaletteControl));
return -1;
}
avctx->pix_fmt = PIX_FMT_PAL8;
avctx->has_b_frames = 0;
dsputil_init(&s->dsp, avctx);
/* initialize the RGB -> YUV tables */
for (i = 0; i < 256; i++) {
y_r_table[i] = Y_R * i;
y_g_table[i] = Y_G * i;
y_b_table[i] = Y_B * i;
u_r_table[i] = U_R * i;
u_g_table[i] = U_G * i;
u_b_table[i] = U_B * i;
v_r_table[i] = V_R * i;
v_g_table[i] = V_G * i;
v_b_table[i] = V_B * i;
}
s->buffer1 = av_malloc(avctx->width * avctx->height);
s->buffer2 = av_malloc(avctx->width * avctx->height);
if (!s->buffer1 || !s->buffer2)
return -1;
return 0;
}
/* This function is used in lieu of memcpy(). This decoder can not use
* memcpy because the memory locations often overlap and
* memcpy doesn't like that; it's not uncommon, for example, for
* dest = src+1, to turn byte A into pattern AAAAAAAA.
* This was originally repz movsb in Intel x86 ASM. */
static inline void bytecopy(unsigned char *dest, unsigned char *src, int count)
{
int i;
for (i = 0; i < count; i++)
dest[i] = src[i];
}
static int xan_huffman_decode(unsigned char *dest, unsigned char *src)
{
unsigned char byte = *src++;
unsigned char ival = byte + 0x16;
unsigned char * ptr = src + byte*2;
unsigned char val = ival;
int counter = 0;
unsigned char bits = *ptr++;
while ( val != 0x16 ) {
if ( (1 << counter) & bits )
val = src[byte + val - 0x17];
else
val = src[val - 0x17];
if ( val < 0x16 ) {
*dest++ = val;
val = ival;
}
if (counter++ == 7) {
counter = 0;
bits = *ptr++;
}
}
return 0;
}
static void xan_unpack(unsigned char *dest, unsigned char *src)
{
unsigned char opcode;
int size;
int offset;
int byte1, byte2, byte3;
for (;;) {
opcode = *src++;
if ( (opcode & 0x80) == 0 ) {
offset = *src++;
size = opcode & 3;
bytecopy(dest, src, size); dest += size; src += size;
size = ((opcode & 0x1c) >> 2) + 3;
bytecopy (dest, dest - (((opcode & 0x60) << 3) + offset + 1), size);
dest += size;
} else if ( (opcode & 0x40) == 0 ) {
byte1 = *src++;
byte2 = *src++;
size = byte1 >> 6;
bytecopy (dest, src, size); dest += size; src += size;
size = (opcode & 0x3f) + 4;
bytecopy (dest, dest - (((byte1 & 0x3f) << 8) + byte2 + 1), size);
dest += size;
} else if ( (opcode & 0x20) == 0 ) {
byte1 = *src++;
byte2 = *src++;
byte3 = *src++;
size = opcode & 3;
bytecopy (dest, src, size); dest += size; src += size;
size = byte3 + 5 + ((opcode & 0xc) << 6);
bytecopy (dest,
dest - ((((opcode & 0x10) >> 4) << 0x10) + 1 + (byte1 << 8) + byte2),
size);
dest += size;
} else {
size = ((opcode & 0x1f) << 2) + 4;
if (size > 0x70)
break;
bytecopy (dest, src, size); dest += size; src += size;
}
}
size = opcode & 3;
bytecopy(dest, src, size); dest += size; src += size;
}
static void inline xan_wc3_build_palette(XanContext *s,
unsigned char *palette_data)
{
int i;
unsigned char r, g, b;
unsigned short *palette16;
unsigned int *palette32;
/* transform the palette passed through the palette control structure
* into the necessary internal format depending on colorspace */
switch (s->avctx->pix_fmt) {
case PIX_FMT_RGB555:
palette16 = (unsigned short *)s->palette;
for (i = 0; i < PALETTE_COUNT; i++) {
r = *palette_data++;
g = *palette_data++;
b = *palette_data++;
palette16[i] =
((r >> 3) << 10) |
((g >> 3) << 5) |
((g >> 3) << 0);
}
break;
case PIX_FMT_RGB565:
palette16 = (unsigned short *)s->palette;
for (i = 0; i < PALETTE_COUNT; i++) {
r = *palette_data++;
g = *palette_data++;
b = *palette_data++;
palette16[i] =
((r >> 3) << 11) |
((g >> 2) << 5) |
((g >> 3) << 0);
}
break;
case PIX_FMT_RGB24:
for (i = 0; i < PALETTE_COUNT; i++) {
s->palette[i * 4 + 0] = *palette_data++;
s->palette[i * 4 + 1] = *palette_data++;
s->palette[i * 4 + 2] = *palette_data++;
}
break;
case PIX_FMT_BGR24:
for (i = 0; i < PALETTE_COUNT; i++) {
r = *palette_data++;
g = *palette_data++;
b = *palette_data++;
s->palette[i * 4 + 0] = b;
s->palette[i * 4 + 1] = g;
s->palette[i * 4 + 2] = r;
}
break;
case PIX_FMT_PAL8:
case PIX_FMT_RGBA32:
palette32 = (unsigned int *)s->palette;
for (i = 0; i < PALETTE_COUNT; i++) {
r = *palette_data++;
g = *palette_data++;
b = *palette_data++;
palette32[i] = (r << 16) | (g << 8) | (b);
}
break;
case PIX_FMT_YUV444P:
for (i = 0; i < PALETTE_COUNT; i++) {
r = *palette_data++;
g = *palette_data++;
b = *palette_data++;
s->palette[i * 4 + 0] = COMPUTE_Y(r, g, b);
s->palette[i * 4 + 1] = COMPUTE_U(r, g, b);
s->palette[i * 4 + 2] = COMPUTE_V(r, g, b);
}
break;
default:
printf (" Xan WC3: Unhandled colorspace\n");
break;
}
}
static void inline xan_wc3_output_pixel_run(XanContext *s,
unsigned char *pixel_buffer, int x, int y, int pixel_count)
{
int stride;
int line_inc;
int index;
int current_x;
int width = s->avctx->width;
unsigned char pixel;
unsigned char *palette_plane;
unsigned char *y_plane;
unsigned char *u_plane;
unsigned char *v_plane;
unsigned char *rgb_plane;
unsigned short *rgb16_plane;
unsigned short *palette16;
unsigned int *rgb32_plane;
unsigned int *palette32;
switch (s->avctx->pix_fmt) {
case PIX_FMT_PAL8:
palette_plane = s->current_frame.data[0];
stride = s->current_frame.linesize[0];
line_inc = stride - width;
index = y * stride + x;
current_x = x;
while(pixel_count--) {
/* don't do a memcpy() here; keyframes generally copy an entire
* frame of data and the stride needs to be accounted for */
palette_plane[index++] = *pixel_buffer++;
current_x++;
if (current_x >= width) {
/* reset accounting variables */
index += line_inc;
current_x = 0;
}
}
break;
case PIX_FMT_RGB555:
case PIX_FMT_RGB565:
rgb16_plane = (unsigned short *)s->current_frame.data[0];
palette16 = (unsigned short *)s->palette;
stride = s->current_frame.linesize[0] / 2;
line_inc = stride - width;
index = y * stride + x;
current_x = x;
while(pixel_count--) {
rgb16_plane[index++] = palette16[*pixel_buffer++];
current_x++;
if (current_x >= width) {
/* reset accounting variables */
index += line_inc;
current_x = 0;
}
}
break;
case PIX_FMT_RGB24:
case PIX_FMT_BGR24:
rgb_plane = s->current_frame.data[0];
stride = s->current_frame.linesize[0];
line_inc = stride - width * 3;
index = y * stride + x * 3;
current_x = x;
while(pixel_count--) {
pixel = *pixel_buffer++;
rgb_plane[index++] = s->palette[pixel * 4 + 0];
rgb_plane[index++] = s->palette[pixel * 4 + 1];
rgb_plane[index++] = s->palette[pixel * 4 + 2];
current_x++;
if (current_x >= width) {
/* reset accounting variables */
index += line_inc;
current_x = 0;
}
}
break;
case PIX_FMT_RGBA32:
rgb32_plane = (unsigned int *)s->current_frame.data[0];
palette32 = (unsigned int *)s->palette;
stride = s->current_frame.linesize[0] / 4;
line_inc = stride - width;
index = y * stride + x;
current_x = x;
while(pixel_count--) {
rgb32_plane[index++] = palette32[*pixel_buffer++];
current_x++;
if (current_x >= width) {
/* reset accounting variables */
index += line_inc;
current_x = 0;
}
}
break;
case PIX_FMT_YUV444P:
y_plane = s->current_frame.data[0];
u_plane = s->current_frame.data[1];
v_plane = s->current_frame.data[2];
stride = s->current_frame.linesize[0];
line_inc = stride - width;
index = y * stride + x;
current_x = x;
while(pixel_count--) {
pixel = *pixel_buffer++;
y_plane[index] = s->palette[pixel * 4 + 0];
u_plane[index] = s->palette[pixel * 4 + 1];
v_plane[index] = s->palette[pixel * 4 + 2];
index++;
current_x++;
if (current_x >= width) {
/* reset accounting variables */
index += line_inc;
current_x = 0;
}
}
break;
default:
printf (" Xan WC3: Unhandled colorspace\n");
break;
}
}
static void inline xan_wc3_copy_pixel_run(XanContext *s,
int x, int y, int pixel_count, int motion_x, int motion_y)
{
int stride;
int line_inc;
int curframe_index, prevframe_index;
int curframe_x, prevframe_x;
int width = s->avctx->width;
unsigned char *palette_plane, *prev_palette_plane;
unsigned char *y_plane, *u_plane, *v_plane;
unsigned char *prev_y_plane, *prev_u_plane, *prev_v_plane;
unsigned char *rgb_plane, *prev_rgb_plane;
unsigned short *rgb16_plane, *prev_rgb16_plane;
unsigned int *rgb32_plane, *prev_rgb32_plane;
switch (s->avctx->pix_fmt) {
case PIX_FMT_PAL8:
palette_plane = s->current_frame.data[0];
prev_palette_plane = s->last_frame.data[0];
stride = s->current_frame.linesize[0];
line_inc = stride - width;
curframe_index = y * stride + x;
curframe_x = x;
prevframe_index = (y + motion_y) * stride + x + motion_x;
prevframe_x = x + motion_x;
while(pixel_count--) {
palette_plane[curframe_index++] =
prev_palette_plane[prevframe_index++];
curframe_x++;
if (curframe_x >= width) {
/* reset accounting variables */
curframe_index += line_inc;
curframe_x = 0;
}
prevframe_x++;
if (prevframe_x >= width) {
/* reset accounting variables */
prevframe_index += line_inc;
prevframe_x = 0;
}
}
break;
case PIX_FMT_RGB555:
case PIX_FMT_RGB565:
rgb16_plane = (unsigned short *)s->current_frame.data[0];
prev_rgb16_plane = (unsigned short *)s->last_frame.data[0];
stride = s->current_frame.linesize[0] / 2;
line_inc = stride - width;
curframe_index = y * stride + x;
curframe_x = x;
prevframe_index = (y + motion_y) * stride + x + motion_x;
prevframe_x = x + motion_x;
while(pixel_count--) {
rgb16_plane[curframe_index++] =
prev_rgb16_plane[prevframe_index++];
curframe_x++;
if (curframe_x >= width) {
/* reset accounting variables */
curframe_index += line_inc;
curframe_x = 0;
}
prevframe_x++;
if (prevframe_x >= width) {
/* reset accounting variables */
prevframe_index += line_inc;
prevframe_x = 0;
}
}
break;
case PIX_FMT_RGB24:
case PIX_FMT_BGR24:
rgb_plane = s->current_frame.data[0];
prev_rgb_plane = s->last_frame.data[0];
stride = s->current_frame.linesize[0];
line_inc = stride - width * 3;
curframe_index = y * stride + x * 3;
curframe_x = x;
prevframe_index = (y + motion_y) * stride +
(3 * (x + motion_x));
prevframe_x = x + motion_x;
while(pixel_count--) {
rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
rgb_plane[curframe_index++] = prev_rgb_plane[prevframe_index++];
curframe_x++;
if (curframe_x >= width) {
/* reset accounting variables */
curframe_index += line_inc;
curframe_x = 0;
}
prevframe_x++;
if (prevframe_x >= width) {
/* reset accounting variables */
prevframe_index += line_inc;
prevframe_x = 0;
}
}
break;
case PIX_FMT_RGBA32:
rgb32_plane = (unsigned int *)s->current_frame.data[0];
prev_rgb32_plane = (unsigned int *)s->last_frame.data[0];
stride = s->current_frame.linesize[0] / 4;
line_inc = stride - width;
curframe_index = y * stride + x;
curframe_x = x;
prevframe_index = (y + motion_y) * stride + x + motion_x;
prevframe_x = x + motion_x;
while(pixel_count--) {
rgb32_plane[curframe_index++] =
prev_rgb32_plane[prevframe_index++];
curframe_x++;
if (curframe_x >= width) {
/* reset accounting variables */
curframe_index += line_inc;
curframe_x = 0;
}
prevframe_x++;
if (prevframe_x >= width) {
/* reset accounting variables */
prevframe_index += line_inc;
prevframe_x = 0;
}
}
break;
case PIX_FMT_YUV444P:
y_plane = s->current_frame.data[0];
u_plane = s->current_frame.data[1];
v_plane = s->current_frame.data[2];
prev_y_plane = s->last_frame.data[0];
prev_u_plane = s->last_frame.data[1];
prev_v_plane = s->last_frame.data[2];
stride = s->current_frame.linesize[0];
line_inc = stride - width;
curframe_index = y * stride + x;
curframe_x = x;
prevframe_index = (y + motion_y) * stride + x + motion_x;
prevframe_x = x + motion_x;
while(pixel_count--) {
y_plane[curframe_index] = prev_y_plane[prevframe_index];
u_plane[curframe_index] = prev_u_plane[prevframe_index];
v_plane[curframe_index] = prev_v_plane[prevframe_index];
curframe_index++;
curframe_x++;
if (curframe_x >= width) {
/* reset accounting variables */
curframe_index += line_inc;
curframe_x = 0;
}
prevframe_index++;
prevframe_x++;
if (prevframe_x >= width) {
/* reset accounting variables */
prevframe_index += line_inc;
prevframe_x = 0;
}
}
break;
default:
printf (" Xan WC3: Unhandled colorspace\n");
break;
}
}
static void xan_wc3_decode_frame(XanContext *s) {
int width = s->avctx->width;
int height = s->avctx->height;
int total_pixels = width * height;
unsigned char opcode;
unsigned char flag = 0;
int size = 0;
int motion_x, motion_y;
int x, y;
unsigned char *opcode_buffer = s->buffer1;
unsigned char *imagedata_buffer = s->buffer2;
/* pointers to segments inside the compressed chunk */
unsigned char *huffman_segment;
unsigned char *size_segment;
unsigned char *vector_segment;
unsigned char *imagedata_segment;
huffman_segment = s->buf + LE_16(&s->buf[0]);
size_segment = s->buf + LE_16(&s->buf[2]);
vector_segment = s->buf + LE_16(&s->buf[4]);
imagedata_segment = s->buf + LE_16(&s->buf[6]);
xan_huffman_decode(opcode_buffer, huffman_segment);
if (imagedata_segment[0] == 2)
xan_unpack(imagedata_buffer, &imagedata_segment[1]);
else
imagedata_buffer = &imagedata_segment[1];
/* use the decoded data segments to build the frame */
x = y = 0;
while (total_pixels) {
opcode = *opcode_buffer++;
size = 0;
switch (opcode) {
case 0:
flag ^= 1;
continue;
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
size = opcode;
break;
case 12:
case 13:
case 14:
case 15:
case 16:
case 17:
case 18:
size += (opcode - 10);
break;
case 9:
case 19:
size = *size_segment++;
break;
case 10:
case 20:
size = BE_16(&size_segment[0]);
size_segment += 2;
break;
case 11:
case 21:
size = (size_segment[0] << 16) | (size_segment[1] << 8) |
size_segment[2];
size_segment += 3;
break;
}
if (opcode < 12) {
flag ^= 1;
if (flag) {
/* run of (size) pixels is unchanged from last frame */
xan_wc3_copy_pixel_run(s, x, y, size, 0, 0);
} else {
/* output a run of pixels from imagedata_buffer */
xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size);
imagedata_buffer += size;
}
} else {
/* run-based motion compensation from last frame */
motion_x = (*vector_segment >> 4) & 0xF;
motion_y = *vector_segment & 0xF;
vector_segment++;
/* sign extension */
if (motion_x & 0x8)
motion_x |= 0xFFFFFFF0;
if (motion_y & 0x8)
motion_y |= 0xFFFFFFF0;
/* copy a run of pixels from the previous frame */
xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y);
flag = 0;
}
/* coordinate accounting */
total_pixels -= size;
while (size) {
if (x + size >= width) {
y++;
size -= (width - x);
x = 0;
} else {
x += size;
size = 0;
}
}
}
/* for PAL8, make the palette available on the way out */
if (s->avctx->pix_fmt == PIX_FMT_PAL8)
memcpy(s->current_frame.data[1], s->palette, PALETTE_COUNT * 4);
}
static void xan_wc4_decode_frame(XanContext *s) {
}
static int xan_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
XanContext *s = avctx->priv_data;
AVPaletteControl *palette_control = (AVPaletteControl *)avctx->extradata;
int keyframe = 0;
if (palette_control->palette_changed) {
/* load the new palette and reset the palette control */
xan_wc3_build_palette(s, palette_control->palette);
palette_control->palette_changed = 0;
keyframe = 1;
}
if (avctx->get_buffer(avctx, &s->current_frame)) {
printf (" Xan Video: get_buffer() failed\n");
return -1;
}
s->current_frame.reference = 3;
s->buf = buf;
s->size = buf_size;
if (avctx->codec->id == CODEC_ID_XAN_WC3)
xan_wc3_decode_frame(s);
else if (avctx->codec->id == CODEC_ID_XAN_WC4)
xan_wc4_decode_frame(s);
/* release the last frame if it is allocated */
if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);
/* shuffle frames */
s->last_frame = s->current_frame;
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->current_frame;
/* always report that the buffer was completely consumed */
return buf_size;
}
static int xan_decode_end(AVCodecContext *avctx)
{
XanContext *s = avctx->priv_data;
/* release the last frame */
avctx->release_buffer(avctx, &s->last_frame);
av_free(s->buffer1);
av_free(s->buffer2);
return 0;
}
AVCodec xan_wc3_decoder = {
"xan_wc3",
CODEC_TYPE_VIDEO,
CODEC_ID_XAN_WC3,
sizeof(XanContext),
xan_decode_init,
NULL,
xan_decode_end,
xan_decode_frame,
CODEC_CAP_DR1,
};
/*
AVCodec xan_wc4_decoder = {
"xan_wc4",
CODEC_TYPE_VIDEO,
CODEC_ID_XAN_WC4,
sizeof(XanContext),
xan_decode_init,
NULL,
xan_decode_end,
xan_decode_frame,
CODEC_CAP_DR1,
};
*/
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