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ffmpeg/libavcodec/interplayvideo.c

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/*
* Interplay MVE 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
/**
* @file interplayvideo.c
* Interplay MVE Video Decoder by Mike Melanson (melanson@pcisys.net)
* For more information about the Interplay MVE format, visit:
* http://www.pcisys.net/~melanson/codecs/interplay-mve.txt
* This code is written in such a way that the identifiers match up
* with the encoding descriptions in the document.
*
* This decoder presently only supports a PAL8 output colorspace.
*
* An Interplay video frame consists of 2 parts: The decoding map and
* the video data. A demuxer must load these 2 parts together in a single
* buffer before sending it through the stream to this decoder.
*/
#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
/* debugging support */
#define DEBUG_INTERPLAY 0
#if DEBUG_INTERPLAY
#define debug_interplay(x,...) av_log(NULL, AV_LOG_DEBUG, x, __VA_ARGS__)
#else
static inline void debug_interplay(const char *format, ...) { }
#endif
typedef struct IpvideoContext {
AVCodecContext *avctx;
DSPContext dsp;
AVFrame second_last_frame;
AVFrame last_frame;
AVFrame current_frame;
unsigned char *decoding_map;
int decoding_map_size;
unsigned char *buf;
int size;
unsigned char *stream_ptr;
unsigned char *stream_end;
unsigned char *pixel_ptr;
int line_inc;
int stride;
int upper_motion_limit_offset;
} IpvideoContext;
#define CHECK_STREAM_PTR(n) \
if ((s->stream_ptr + n) > s->stream_end) { \
av_log(s->avctx, AV_LOG_ERROR, "Interplay video warning: stream_ptr out of bounds (%p >= %p)\n", \
s->stream_ptr + n, s->stream_end); \
return -1; \
}
#define COPY_FROM_CURRENT() \
motion_offset = current_offset; \
motion_offset += y * s->stride; \
motion_offset += x; \
if (motion_offset < 0) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
return -1; \
} else if (motion_offset > s->upper_motion_limit_offset) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
motion_offset, s->upper_motion_limit_offset); \
return -1; \
} \
s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
s->current_frame.data[0] + motion_offset, s->stride, 8);
#define COPY_FROM_PREVIOUS() \
motion_offset = current_offset; \
motion_offset += y * s->stride; \
motion_offset += x; \
if (motion_offset < 0) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
return -1; \
} else if (motion_offset > s->upper_motion_limit_offset) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
motion_offset, s->upper_motion_limit_offset); \
return -1; \
} \
s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
s->last_frame.data[0] + motion_offset, s->stride, 8);
#define COPY_FROM_SECOND_LAST() \
motion_offset = current_offset; \
motion_offset += y * s->stride; \
motion_offset += x; \
if (motion_offset < 0) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset < 0 (%d)\n", motion_offset); \
return -1; \
} else if (motion_offset > s->upper_motion_limit_offset) { \
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: motion offset above limit (%d >= %d)\n", \
motion_offset, s->upper_motion_limit_offset); \
return -1; \
} \
s->dsp.put_pixels_tab[0][0](s->pixel_ptr, \
s->second_last_frame.data[0] + motion_offset, s->stride, 8);
static int ipvideo_decode_block_opcode_0x0(IpvideoContext *s)
{
int x, y;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy a block from the previous frame */
x = y = 0;
COPY_FROM_PREVIOUS();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x1(IpvideoContext *s)
{
int x, y;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy block from 2 frames ago */
x = y = 0;
COPY_FROM_SECOND_LAST();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x2(IpvideoContext *s)
{
unsigned char B;
int x, y;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy block from 2 frames ago using a motion vector; need 1 more byte */
CHECK_STREAM_PTR(1);
B = *s->stream_ptr++;
if (B < 56) {
x = 8 + (B % 7);
y = B / 7;
} else {
x = -14 + ((B - 56) % 29);
y = 8 + ((B - 56) / 29);
}
debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
COPY_FROM_SECOND_LAST();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x3(IpvideoContext *s)
{
unsigned char B;
int x, y;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy 8x8 block from current frame from an up/left block */
/* need 1 more byte for motion */
CHECK_STREAM_PTR(1);
B = *s->stream_ptr++;
if (B < 56) {
x = -(8 + (B % 7));
y = -(B / 7);
} else {
x = -(-14 + ((B - 56) % 29));
y = -( 8 + ((B - 56) / 29));
}
debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
COPY_FROM_CURRENT();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x4(IpvideoContext *s)
{
int x, y;
unsigned char B, BL, BH;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy a block from the previous frame; need 1 more byte */
CHECK_STREAM_PTR(1);
B = *s->stream_ptr++;
BL = B & 0x0F;
BH = (B >> 4) & 0x0F;
x = -8 + BL;
y = -8 + BH;
debug_interplay (" motion byte = %d, (x, y) = (%d, %d)\n", B, x, y);
COPY_FROM_PREVIOUS();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x5(IpvideoContext *s)
{
signed char x, y;
int motion_offset;
int current_offset = s->pixel_ptr - s->current_frame.data[0];
/* copy a block from the previous frame using an expanded range;
* need 2 more bytes */
CHECK_STREAM_PTR(2);
x = *s->stream_ptr++;
y = *s->stream_ptr++;
debug_interplay (" motion bytes = %d, %d\n", x, y);
COPY_FROM_PREVIOUS();
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x6(IpvideoContext *s)
{
/* mystery opcode? skip multiple blocks? */
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: Help! Mystery opcode 0x6 seen\n");
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x7(IpvideoContext *s)
{
int x, y;
unsigned char P0, P1;
unsigned char B[8];
unsigned int flags;
int bitmask;
/* 2-color encoding */
CHECK_STREAM_PTR(2);
P0 = *s->stream_ptr++;
P1 = *s->stream_ptr++;
if (P0 <= P1) {
/* need 8 more bytes from the stream */
CHECK_STREAM_PTR(8);
for (y = 0; y < 8; y++)
B[y] = *s->stream_ptr++;
for (y = 0; y < 8; y++) {
flags = B[y];
for (x = 0x01; x <= 0x80; x <<= 1) {
if (flags & x)
*s->pixel_ptr++ = P1;
else
*s->pixel_ptr++ = P0;
}
s->pixel_ptr += s->line_inc;
}
} else {
/* need 2 more bytes from the stream */
CHECK_STREAM_PTR(2);
B[0] = *s->stream_ptr++;
B[1] = *s->stream_ptr++;
flags = (B[1] << 8) | B[0];
bitmask = 0x0001;
for (y = 0; y < 8; y += 2) {
for (x = 0; x < 8; x += 2, bitmask <<= 1) {
if (flags & bitmask) {
*(s->pixel_ptr + x) = P1;
*(s->pixel_ptr + x + 1) = P1;
*(s->pixel_ptr + s->stride + x) = P1;
*(s->pixel_ptr + s->stride + x + 1) = P1;
} else {
*(s->pixel_ptr + x) = P0;
*(s->pixel_ptr + x + 1) = P0;
*(s->pixel_ptr + s->stride + x) = P0;
*(s->pixel_ptr + s->stride + x + 1) = P0;
}
}
s->pixel_ptr += s->stride * 2;
}
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x8(IpvideoContext *s)
{
int x, y;
unsigned char P[8];
unsigned char B[8];
unsigned int flags = 0;
unsigned int bitmask = 0;
unsigned char P0 = 0, P1 = 0;
int lower_half = 0;
/* 2-color encoding for each 4x4 quadrant, or 2-color encoding on
* either top and bottom or left and right halves */
CHECK_STREAM_PTR(2);
P[0] = *s->stream_ptr++;
P[1] = *s->stream_ptr++;
if (P[0] <= P[1]) {
/* need 12 more bytes */
CHECK_STREAM_PTR(12);
B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++;
P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
P[4] = *s->stream_ptr++; P[5] = *s->stream_ptr++;
B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
P[6] = *s->stream_ptr++; P[7] = *s->stream_ptr++;
B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
for (y = 0; y < 8; y++) {
/* time to reload flags? */
if (y == 0) {
flags =
((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
bitmask = 0x00000001;
lower_half = 0; /* still on top half */
} else if (y == 4) {
flags =
((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
bitmask = 0x00000001;
lower_half = 2;
}
for (x = 0; x < 8; x++, bitmask <<= 1) {
/* get the pixel values ready for this quadrant */
if (x == 0) {
P0 = P[lower_half + 0];
P1 = P[lower_half + 1];
} else if (x == 4) {
P0 = P[lower_half + 4];
P1 = P[lower_half + 5];
}
if (flags & bitmask)
*s->pixel_ptr++ = P1;
else
*s->pixel_ptr++ = P0;
}
s->pixel_ptr += s->line_inc;
}
} else {
/* need 10 more bytes */
CHECK_STREAM_PTR(10);
B[0] = *s->stream_ptr++; B[1] = *s->stream_ptr++;
B[2] = *s->stream_ptr++; B[3] = *s->stream_ptr++;
P[2] = *s->stream_ptr++; P[3] = *s->stream_ptr++;
B[4] = *s->stream_ptr++; B[5] = *s->stream_ptr++;
B[6] = *s->stream_ptr++; B[7] = *s->stream_ptr++;
if (P[2] <= P[3]) {
/* vertical split; left & right halves are 2-color encoded */
for (y = 0; y < 8; y++) {
/* time to reload flags? */
if (y == 0) {
flags =
((B[0] & 0xF0) << 4) | ((B[4] & 0xF0) << 8) |
((B[0] & 0x0F) ) | ((B[4] & 0x0F) << 4) |
((B[1] & 0xF0) << 20) | ((B[5] & 0xF0) << 24) |
((B[1] & 0x0F) << 16) | ((B[5] & 0x0F) << 20);
bitmask = 0x00000001;
} else if (y == 4) {
flags =
((B[2] & 0xF0) << 4) | ((B[6] & 0xF0) << 8) |
((B[2] & 0x0F) ) | ((B[6] & 0x0F) << 4) |
((B[3] & 0xF0) << 20) | ((B[7] & 0xF0) << 24) |
((B[3] & 0x0F) << 16) | ((B[7] & 0x0F) << 20);
bitmask = 0x00000001;
}
for (x = 0; x < 8; x++, bitmask <<= 1) {
/* get the pixel values ready for this half */
if (x == 0) {
P0 = P[0];
P1 = P[1];
} else if (x == 4) {
P0 = P[2];
P1 = P[3];
}
if (flags & bitmask)
*s->pixel_ptr++ = P1;
else
*s->pixel_ptr++ = P0;
}
s->pixel_ptr += s->line_inc;
}
} else {
/* horizontal split; top & bottom halves are 2-color encoded */
for (y = 0; y < 8; y++) {
flags = B[y];
if (y == 0) {
P0 = P[0];
P1 = P[1];
} else if (y == 4) {
P0 = P[2];
P1 = P[3];
}
for (bitmask = 0x01; bitmask <= 0x80; bitmask <<= 1) {
if (flags & bitmask)
*s->pixel_ptr++ = P1;
else
*s->pixel_ptr++ = P0;
}
s->pixel_ptr += s->line_inc;
}
}
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0x9(IpvideoContext *s)
{
int x, y;
unsigned char P[4];
unsigned char B[4];
unsigned int flags = 0;
int shifter = 0;
unsigned char pix;
/* 4-color encoding */
CHECK_STREAM_PTR(4);
for (y = 0; y < 4; y++)
P[y] = *s->stream_ptr++;
if ((P[0] <= P[1]) && (P[2] <= P[3])) {
/* 1 of 4 colors for each pixel, need 16 more bytes */
CHECK_STREAM_PTR(16);
for (y = 0; y < 8; y++) {
/* get the next set of 8 2-bit flags */
flags = (s->stream_ptr[1] << 8) | s->stream_ptr[0];
s->stream_ptr += 2;
for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
*s->pixel_ptr++ = P[(flags >> shifter) & 0x03];
}
s->pixel_ptr += s->line_inc;
}
} else if ((P[0] <= P[1]) && (P[2] > P[3])) {
/* 1 of 4 colors for each 2x2 block, need 4 more bytes */
CHECK_STREAM_PTR(4);
B[0] = *s->stream_ptr++;
B[1] = *s->stream_ptr++;
B[2] = *s->stream_ptr++;
B[3] = *s->stream_ptr++;
flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
shifter = 0;
for (y = 0; y < 8; y += 2) {
for (x = 0; x < 8; x += 2, shifter += 2) {
pix = P[(flags >> shifter) & 0x03];
*(s->pixel_ptr + x) = pix;
*(s->pixel_ptr + x + 1) = pix;
*(s->pixel_ptr + s->stride + x) = pix;
*(s->pixel_ptr + s->stride + x + 1) = pix;
}
s->pixel_ptr += s->stride * 2;
}
} else if ((P[0] > P[1]) && (P[2] <= P[3])) {
/* 1 of 4 colors for each 2x1 block, need 8 more bytes */
CHECK_STREAM_PTR(8);
for (y = 0; y < 8; y++) {
/* time to reload flags? */
if ((y == 0) || (y == 4)) {
B[0] = *s->stream_ptr++;
B[1] = *s->stream_ptr++;
B[2] = *s->stream_ptr++;
B[3] = *s->stream_ptr++;
flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
shifter = 0;
}
for (x = 0; x < 8; x += 2, shifter += 2) {
pix = P[(flags >> shifter) & 0x03];
*(s->pixel_ptr + x) = pix;
*(s->pixel_ptr + x + 1) = pix;
}
s->pixel_ptr += s->stride;
}
} else {
/* 1 of 4 colors for each 1x2 block, need 8 more bytes */
CHECK_STREAM_PTR(8);
for (y = 0; y < 8; y += 2) {
/* time to reload flags? */
if ((y == 0) || (y == 4)) {
B[0] = *s->stream_ptr++;
B[1] = *s->stream_ptr++;
B[2] = *s->stream_ptr++;
B[3] = *s->stream_ptr++;
flags = (B[3] << 24) | (B[2] << 16) | (B[1] << 8) | B[0];
shifter = 0;
}
for (x = 0; x < 8; x++, shifter += 2) {
pix = P[(flags >> shifter) & 0x03];
*(s->pixel_ptr + x) = pix;
*(s->pixel_ptr + s->stride + x) = pix;
}
s->pixel_ptr += s->stride * 2;
}
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xA(IpvideoContext *s)
{
int x, y;
unsigned char P[16];
unsigned char B[16];
int flags = 0;
int shifter = 0;
int index;
int split;
int lower_half;
/* 4-color encoding for each 4x4 quadrant, or 4-color encoding on
* either top and bottom or left and right halves */
CHECK_STREAM_PTR(4);
for (y = 0; y < 4; y++)
P[y] = *s->stream_ptr++;
if (P[0] <= P[1]) {
/* 4-color encoding for each quadrant; need 28 more bytes */
CHECK_STREAM_PTR(28);
for (y = 0; y < 4; y++)
B[y] = *s->stream_ptr++;
for (y = 4; y < 16; y += 4) {
for (x = y; x < y + 4; x++)
P[x] = *s->stream_ptr++;
for (x = y; x < y + 4; x++)
B[x] = *s->stream_ptr++;
}
for (y = 0; y < 8; y++) {
lower_half = (y >= 4) ? 4 : 0;
flags = (B[y + 8] << 8) | B[y];
for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
split = (x >= 4) ? 8 : 0;
index = split + lower_half + ((flags >> shifter) & 0x03);
*s->pixel_ptr++ = P[index];
}
s->pixel_ptr += s->line_inc;
}
} else {
/* 4-color encoding for either left and right or top and bottom
* halves; need 20 more bytes */
CHECK_STREAM_PTR(20);
for (y = 0; y < 8; y++)
B[y] = *s->stream_ptr++;
for (y = 4; y < 8; y++)
P[y] = *s->stream_ptr++;
for (y = 8; y < 16; y++)
B[y] = *s->stream_ptr++;
if (P[4] <= P[5]) {
/* block is divided into left and right halves */
for (y = 0; y < 8; y++) {
flags = (B[y + 8] << 8) | B[y];
split = 0;
for (x = 0, shifter = 0; x < 8; x++, shifter += 2) {
if (x == 4)
split = 4;
*s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
}
s->pixel_ptr += s->line_inc;
}
} else {
/* block is divided into top and bottom halves */
split = 0;
for (y = 0; y < 8; y++) {
flags = (B[y * 2 + 1] << 8) | B[y * 2];
if (y == 4)
split = 4;
for (x = 0, shifter = 0; x < 8; x++, shifter += 2)
*s->pixel_ptr++ = P[split + ((flags >> shifter) & 0x03)];
s->pixel_ptr += s->line_inc;
}
}
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xB(IpvideoContext *s)
{
int x, y;
/* 64-color encoding (each pixel in block is a different color) */
CHECK_STREAM_PTR(64);
for (y = 0; y < 8; y++) {
for (x = 0; x < 8; x++) {
*s->pixel_ptr++ = *s->stream_ptr++;
}
s->pixel_ptr += s->line_inc;
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xC(IpvideoContext *s)
{
int x, y;
unsigned char pix;
/* 16-color block encoding: each 2x2 block is a different color */
CHECK_STREAM_PTR(16);
for (y = 0; y < 8; y += 2) {
for (x = 0; x < 8; x += 2) {
pix = *s->stream_ptr++;
*(s->pixel_ptr + x) = pix;
*(s->pixel_ptr + x + 1) = pix;
*(s->pixel_ptr + s->stride + x) = pix;
*(s->pixel_ptr + s->stride + x + 1) = pix;
}
s->pixel_ptr += s->stride * 2;
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xD(IpvideoContext *s)
{
int x, y;
unsigned char P[4];
unsigned char index = 0;
/* 4-color block encoding: each 4x4 block is a different color */
CHECK_STREAM_PTR(4);
for (y = 0; y < 4; y++)
P[y] = *s->stream_ptr++;
for (y = 0; y < 8; y++) {
if (y < 4)
index = 0;
else
index = 2;
for (x = 0; x < 8; x++) {
if (x == 4)
index++;
*s->pixel_ptr++ = P[index];
}
s->pixel_ptr += s->line_inc;
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xE(IpvideoContext *s)
{
int x, y;
unsigned char pix;
/* 1-color encoding: the whole block is 1 solid color */
CHECK_STREAM_PTR(1);
pix = *s->stream_ptr++;
for (y = 0; y < 8; y++) {
for (x = 0; x < 8; x++) {
*s->pixel_ptr++ = pix;
}
s->pixel_ptr += s->line_inc;
}
/* report success */
return 0;
}
static int ipvideo_decode_block_opcode_0xF(IpvideoContext *s)
{
int x, y;
unsigned char sample0, sample1;
/* dithered encoding */
CHECK_STREAM_PTR(2);
sample0 = *s->stream_ptr++;
sample1 = *s->stream_ptr++;
for (y = 0; y < 8; y++) {
for (x = 0; x < 8; x += 2) {
if (y & 1) {
*s->pixel_ptr++ = sample1;
*s->pixel_ptr++ = sample0;
} else {
*s->pixel_ptr++ = sample0;
*s->pixel_ptr++ = sample1;
}
}
s->pixel_ptr += s->line_inc;
}
/* report success */
return 0;
}
static int (*ipvideo_decode_block[16])(IpvideoContext *s);
static void ipvideo_decode_opcodes(IpvideoContext *s)
{
int x, y;
int index = 0;
unsigned char opcode;
int ret;
int code_counts[16];
static int frame = 0;
debug_interplay("------------------ frame %d\n", frame);
frame++;
for (x = 0; x < 16; x++)
code_counts[x] = 0;
/* this is PAL8, so make the palette available */
memcpy(s->current_frame.data[1], s->avctx->palctrl->palette, PALETTE_COUNT * 4);
s->stride = s->current_frame.linesize[0];
s->stream_ptr = s->buf + 14; /* data starts 14 bytes in */
s->stream_end = s->buf + s->size;
s->line_inc = s->stride - 8;
s->upper_motion_limit_offset = (s->avctx->height - 8) * s->stride
+ s->avctx->width - 8;
s->dsp = s->dsp;
for (y = 0; y < (s->stride * s->avctx->height); y += s->stride * 8) {
for (x = y; x < y + s->avctx->width; x += 8) {
/* bottom nibble first, then top nibble (which makes it
* hard to use a GetBitcontext) */
if (index & 1)
opcode = s->decoding_map[index >> 1] >> 4;
else
opcode = s->decoding_map[index >> 1] & 0xF;
index++;
debug_interplay(" block @ (%3d, %3d): encoding 0x%X, data ptr @ %p\n",
x - y, y / s->stride, opcode, s->stream_ptr);
code_counts[opcode]++;
s->pixel_ptr = s->current_frame.data[0] + x;
ret = ipvideo_decode_block[opcode](s);
if (ret != 0) {
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode problem on frame %d, @ block (%d, %d)\n",
frame, x - y, y / s->stride);
return;
}
}
}
if ((s->stream_ptr != s->stream_end) &&
(s->stream_ptr + 1 != s->stream_end)) {
av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %td bytes left over\n",
s->stream_end - s->stream_ptr);
}
}
static int ipvideo_decode_init(AVCodecContext *avctx)
{
IpvideoContext *s = avctx->priv_data;
s->avctx = avctx;
if (s->avctx->palctrl == NULL) {
av_log(avctx, AV_LOG_ERROR, " Interplay video: palette expected.\n");
return -1;
}
avctx->pix_fmt = PIX_FMT_PAL8;
avctx->has_b_frames = 0;
dsputil_init(&s->dsp, avctx);
/* decoding map contains 4 bits of information per 8x8 block */
s->decoding_map_size = avctx->width * avctx->height / (8 * 8 * 2);
/* assign block decode functions */
ipvideo_decode_block[0x0] = ipvideo_decode_block_opcode_0x0;
ipvideo_decode_block[0x1] = ipvideo_decode_block_opcode_0x1;
ipvideo_decode_block[0x2] = ipvideo_decode_block_opcode_0x2;
ipvideo_decode_block[0x3] = ipvideo_decode_block_opcode_0x3;
ipvideo_decode_block[0x4] = ipvideo_decode_block_opcode_0x4;
ipvideo_decode_block[0x5] = ipvideo_decode_block_opcode_0x5;
ipvideo_decode_block[0x6] = ipvideo_decode_block_opcode_0x6;
ipvideo_decode_block[0x7] = ipvideo_decode_block_opcode_0x7;
ipvideo_decode_block[0x8] = ipvideo_decode_block_opcode_0x8;
ipvideo_decode_block[0x9] = ipvideo_decode_block_opcode_0x9;
ipvideo_decode_block[0xA] = ipvideo_decode_block_opcode_0xA;
ipvideo_decode_block[0xB] = ipvideo_decode_block_opcode_0xB;
ipvideo_decode_block[0xC] = ipvideo_decode_block_opcode_0xC;
ipvideo_decode_block[0xD] = ipvideo_decode_block_opcode_0xD;
ipvideo_decode_block[0xE] = ipvideo_decode_block_opcode_0xE;
ipvideo_decode_block[0xF] = ipvideo_decode_block_opcode_0xF;
s->current_frame.data[0] = s->last_frame.data[0] =
s->second_last_frame.data[0] = NULL;
return 0;
}
static int ipvideo_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
IpvideoContext *s = avctx->priv_data;
AVPaletteControl *palette_control = avctx->palctrl;
/* compressed buffer needs to be large enough to at least hold an entire
* decoding map */
if (buf_size < s->decoding_map_size)
return buf_size;
s->decoding_map = buf;
s->buf = buf + s->decoding_map_size;
s->size = buf_size - s->decoding_map_size;
s->current_frame.reference = 3;
if (avctx->get_buffer(avctx, &s->current_frame)) {
av_log(avctx, AV_LOG_ERROR, " Interplay Video: get_buffer() failed\n");
return -1;
}
ipvideo_decode_opcodes(s);
if (palette_control->palette_changed) {
palette_control->palette_changed = 0;
s->current_frame.palette_has_changed = 1;
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->current_frame;
/* shuffle frames */
if (s->second_last_frame.data[0])
avctx->release_buffer(avctx, &s->second_last_frame);
s->second_last_frame = s->last_frame;
s->last_frame = s->current_frame;
s->current_frame.data[0] = NULL; /* catch any access attempts */
/* report that the buffer was completely consumed */
return buf_size;
}
static int ipvideo_decode_end(AVCodecContext *avctx)
{
IpvideoContext *s = avctx->priv_data;
/* release the last frame */
if (s->last_frame.data[0])
avctx->release_buffer(avctx, &s->last_frame);
if (s->second_last_frame.data[0])
avctx->release_buffer(avctx, &s->second_last_frame);
return 0;
}
AVCodec interplay_video_decoder = {
"interplayvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_INTERPLAY_VIDEO,
sizeof(IpvideoContext),
ipvideo_decode_init,
NULL,
ipvideo_decode_end,
ipvideo_decode_frame,
CODEC_CAP_DR1,
};
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