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ffmpeg/libavcodec/vqavideo.c

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/*
* Westwood Studios VQA Video Decoder
* Copyright (C) 2003 the ffmpeg project
*
* 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 libavcodec/vqavideo.c
* VQA Video Decoder by Mike Melanson (melanson@pcisys.net)
* For more information about the VQA format, visit:
* http://wiki.multimedia.cx/index.php?title=VQA
*
* The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending
* on the type of data in the file.
*
* This decoder needs the 42-byte VQHD header from the beginning
* of the VQA file passed through the extradata field. The VQHD header
* is laid out as:
*
* bytes 0-3 chunk fourcc: 'VQHD'
* bytes 4-7 chunk size in big-endian format, should be 0x0000002A
* bytes 8-49 VQHD chunk data
*
* Bytes 8-49 are what this decoder expects to see.
*
* Briefly, VQA is a vector quantized animation format that operates in a
* VGA palettized colorspace. It operates on pixel vectors (blocks)
* of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector
* codebooks, palette information, and code maps for rendering vectors onto
* frames. Any of these components can also be compressed with a run-length
* encoding (RLE) algorithm commonly referred to as "format80".
*
* VQA takes a novel approach to rate control. Each group of n frames
* (usually, n = 8) relies on a different vector codebook. Rather than
* transporting an entire codebook every 8th frame, the new codebook is
* broken up into 8 pieces and sent along with the compressed video chunks
* for each of the 8 frames preceding the 8 frames which require the
* codebook. A full codebook is also sent on the very first frame of a
* file. This is an interesting technique, although it makes random file
* seeking difficult despite the fact that the frames are all intracoded.
*
* V1,2 VQA uses 12-bit codebook indexes. If the 12-bit indexes were
* packed into bytes and then RLE compressed, bytewise, the results would
* be poor. That is why the coding method divides each index into 2 parts,
* the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces
* together and the 8-bit pieces together. If most of the vectors are
* clustered into one group of 256 vectors, most of the 4-bit index pieces
* should be the same.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#define PALETTE_COUNT 256
#define VQA_HEADER_SIZE 0x2A
#define CHUNK_PREAMBLE_SIZE 8
/* allocate the maximum vector space, regardless of the file version:
* (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */
#define MAX_CODEBOOK_VECTORS 0xFF00
#define SOLID_PIXEL_VECTORS 0x100
#define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS)
#define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4)
#define CBF0_TAG MKBETAG('C', 'B', 'F', '0')
#define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z')
#define CBP0_TAG MKBETAG('C', 'B', 'P', '0')
#define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z')
#define CPL0_TAG MKBETAG('C', 'P', 'L', '0')
#define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z')
#define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z')
#define VQA_DEBUG 0
#if VQA_DEBUG
#define vqa_debug printf
#else
static inline void vqa_debug(const char *format, ...) { }
#endif
typedef struct VqaContext {
AVCodecContext *avctx;
AVFrame frame;
const unsigned char *buf;
int size;
uint32_t palette[PALETTE_COUNT];
int width; /* width of a frame */
int height; /* height of a frame */
int vector_width; /* width of individual vector */
int vector_height; /* height of individual vector */
int vqa_version; /* this should be either 1, 2 or 3 */
unsigned char *codebook; /* the current codebook */
int codebook_size;
unsigned char *next_codebook_buffer; /* accumulator for next codebook */
int next_codebook_buffer_index;
unsigned char *decode_buffer;
int decode_buffer_size;
/* number of frames to go before replacing codebook */
int partial_countdown;
int partial_count;
} VqaContext;
static av_cold int vqa_decode_init(AVCodecContext *avctx)
{
VqaContext *s = avctx->priv_data;
unsigned char *vqa_header;
int i, j, codebook_index;
s->avctx = avctx;
avctx->pix_fmt = PIX_FMT_PAL8;
/* make sure the extradata made it */
if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
av_log(s->avctx, AV_LOG_ERROR, " VQA video: expected extradata size of %d\n", VQA_HEADER_SIZE);
return -1;
}
/* load up the VQA parameters from the header */
vqa_header = (unsigned char *)s->avctx->extradata;
s->vqa_version = vqa_header[0];
s->width = AV_RL16(&vqa_header[6]);
s->height = AV_RL16(&vqa_header[8]);
if(avcodec_check_dimensions(avctx, s->width, s->height)){
s->width= s->height= 0;
return -1;
}
s->vector_width = vqa_header[10];
s->vector_height = vqa_header[11];
s->partial_count = s->partial_countdown = vqa_header[13];
/* the vector dimensions have to meet very stringent requirements */
if ((s->vector_width != 4) ||
((s->vector_height != 2) && (s->vector_height != 4))) {
/* return without further initialization */
return -1;
}
/* allocate codebooks */
s->codebook_size = MAX_CODEBOOK_SIZE;
s->codebook = av_malloc(s->codebook_size);
s->next_codebook_buffer = av_malloc(s->codebook_size);
/* initialize the solid-color vectors */
if (s->vector_height == 4) {
codebook_index = 0xFF00 * 16;
for (i = 0; i < 256; i++)
for (j = 0; j < 16; j++)
s->codebook[codebook_index++] = i;
} else {
codebook_index = 0xF00 * 8;
for (i = 0; i < 256; i++)
for (j = 0; j < 8; j++)
s->codebook[codebook_index++] = i;
}
s->next_codebook_buffer_index = 0;
/* allocate decode buffer */
s->decode_buffer_size = (s->width / s->vector_width) *
(s->height / s->vector_height) * 2;
s->decode_buffer = av_malloc(s->decode_buffer_size);
s->frame.data[0] = NULL;
return 0;
}
#define CHECK_COUNT() \
if (dest_index + count > dest_size) { \
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: next op would overflow dest_index\n"); \
av_log(NULL, AV_LOG_ERROR, " VQA video: current dest_index = %d, count = %d, dest_size = %d\n", \
dest_index, count, dest_size); \
return; \
}
static void decode_format80(const unsigned char *src, int src_size,
unsigned char *dest, int dest_size, int check_size) {
int src_index = 0;
int dest_index = 0;
int count;
int src_pos;
unsigned char color;
int i;
while (src_index < src_size) {
vqa_debug(" opcode %02X: ", src[src_index]);
/* 0x80 means that frame is finished */
if (src[src_index] == 0x80)
return;
if (dest_index >= dest_size) {
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
dest_index, dest_size);
return;
}
if (src[src_index] == 0xFF) {
src_index++;
count = AV_RL16(&src[src_index]);
src_index += 2;
src_pos = AV_RL16(&src[src_index]);
src_index += 2;
vqa_debug("(1) copy %X bytes from absolute pos %X\n", count, src_pos);
CHECK_COUNT();
for (i = 0; i < count; i++)
dest[dest_index + i] = dest[src_pos + i];
dest_index += count;
} else if (src[src_index] == 0xFE) {
src_index++;
count = AV_RL16(&src[src_index]);
src_index += 2;
color = src[src_index++];
vqa_debug("(2) set %X bytes to %02X\n", count, color);
CHECK_COUNT();
memset(&dest[dest_index], color, count);
dest_index += count;
} else if ((src[src_index] & 0xC0) == 0xC0) {
count = (src[src_index++] & 0x3F) + 3;
src_pos = AV_RL16(&src[src_index]);
src_index += 2;
vqa_debug("(3) copy %X bytes from absolute pos %X\n", count, src_pos);
CHECK_COUNT();
for (i = 0; i < count; i++)
dest[dest_index + i] = dest[src_pos + i];
dest_index += count;
} else if (src[src_index] > 0x80) {
count = src[src_index++] & 0x3F;
vqa_debug("(4) copy %X bytes from source to dest\n", count);
CHECK_COUNT();
memcpy(&dest[dest_index], &src[src_index], count);
src_index += count;
dest_index += count;
} else {
count = ((src[src_index] & 0x70) >> 4) + 3;
src_pos = AV_RB16(&src[src_index]) & 0x0FFF;
src_index += 2;
vqa_debug("(5) copy %X bytes from relpos %X\n", count, src_pos);
CHECK_COUNT();
for (i = 0; i < count; i++)
dest[dest_index + i] = dest[dest_index - src_pos + i];
dest_index += count;
}
}
/* validate that the entire destination buffer was filled; this is
* important for decoding frame maps since each vector needs to have a
* codebook entry; it is not important for compressed codebooks because
* not every entry needs to be filled */
if (check_size)
if (dest_index < dest_size)
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
dest_index, dest_size);
}
static void vqa_decode_chunk(VqaContext *s)
{
unsigned int chunk_type;
unsigned int chunk_size;
int byte_skip;
unsigned int index = 0;
int i;
unsigned char r, g, b;
int index_shift;
int cbf0_chunk = -1;
int cbfz_chunk = -1;
int cbp0_chunk = -1;
int cbpz_chunk = -1;
int cpl0_chunk = -1;
int cplz_chunk = -1;
int vptz_chunk = -1;
int x, y;
int lines = 0;
int pixel_ptr;
int vector_index = 0;
int lobyte = 0;
int hibyte = 0;
int lobytes = 0;
int hibytes = s->decode_buffer_size / 2;
/* first, traverse through the frame and find the subchunks */
while (index < s->size) {
chunk_type = AV_RB32(&s->buf[index]);
chunk_size = AV_RB32(&s->buf[index + 4]);
switch (chunk_type) {
case CBF0_TAG:
cbf0_chunk = index;
break;
case CBFZ_TAG:
cbfz_chunk = index;
break;
case CBP0_TAG:
cbp0_chunk = index;
break;
case CBPZ_TAG:
cbpz_chunk = index;
break;
case CPL0_TAG:
cpl0_chunk = index;
break;
case CPLZ_TAG:
cplz_chunk = index;
break;
case VPTZ_TAG:
vptz_chunk = index;
break;
default:
av_log(s->avctx, AV_LOG_ERROR, " VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n",
(chunk_type >> 24) & 0xFF,
(chunk_type >> 16) & 0xFF,
(chunk_type >> 8) & 0xFF,
(chunk_type >> 0) & 0xFF,
chunk_type);
break;
}
byte_skip = chunk_size & 0x01;
index += (CHUNK_PREAMBLE_SIZE + chunk_size + byte_skip);
}
/* next, deal with the palette */
if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
/* a chunk should not have both chunk types */
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CPL0 and CPLZ chunks\n");
return;
}
/* decompress the palette chunk */
if (cplz_chunk != -1) {
/* yet to be handled */
}
/* convert the RGB palette into the machine's endian format */
if (cpl0_chunk != -1) {
chunk_size = AV_RB32(&s->buf[cpl0_chunk + 4]);
/* sanity check the palette size */
if (chunk_size / 3 > 256) {
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found a palette chunk with %d colors\n",
chunk_size / 3);
return;
}
cpl0_chunk += CHUNK_PREAMBLE_SIZE;
for (i = 0; i < chunk_size / 3; i++) {
/* scale by 4 to transform 6-bit palette -> 8-bit */
r = s->buf[cpl0_chunk++] * 4;
g = s->buf[cpl0_chunk++] * 4;
b = s->buf[cpl0_chunk++] * 4;
s->palette[i] = (r << 16) | (g << 8) | (b);
}
}
/* next, look for a full codebook */
if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
/* a chunk should not have both chunk types */
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBF0 and CBFZ chunks\n");
return;
}
/* decompress the full codebook chunk */
if (cbfz_chunk != -1) {
chunk_size = AV_RB32(&s->buf[cbfz_chunk + 4]);
cbfz_chunk += CHUNK_PREAMBLE_SIZE;
decode_format80(&s->buf[cbfz_chunk], chunk_size,
s->codebook, s->codebook_size, 0);
}
/* copy a full codebook */
if (cbf0_chunk != -1) {
chunk_size = AV_RB32(&s->buf[cbf0_chunk + 4]);
/* sanity check the full codebook size */
if (chunk_size > MAX_CODEBOOK_SIZE) {
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: CBF0 chunk too large (0x%X bytes)\n",
chunk_size);
return;
}
cbf0_chunk += CHUNK_PREAMBLE_SIZE;
memcpy(s->codebook, &s->buf[cbf0_chunk], chunk_size);
}
/* decode the frame */
if (vptz_chunk == -1) {
/* something is wrong if there is no VPTZ chunk */
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: no VPTZ chunk found\n");
return;
}
chunk_size = AV_RB32(&s->buf[vptz_chunk + 4]);
vptz_chunk += CHUNK_PREAMBLE_SIZE;
decode_format80(&s->buf[vptz_chunk], chunk_size,
s->decode_buffer, s->decode_buffer_size, 1);
/* render the final PAL8 frame */
if (s->vector_height == 4)
index_shift = 4;
else
index_shift = 3;
for (y = 0; y < s->frame.linesize[0] * s->height;
y += s->frame.linesize[0] * s->vector_height) {
for (x = y; x < y + s->width; x += 4, lobytes++, hibytes++) {
pixel_ptr = x;
/* get the vector index, the method for which varies according to
* VQA file version */
switch (s->vqa_version) {
case 1:
/* still need sample media for this case (only one game, "Legend of
* Kyrandia III : Malcolm's Revenge", is known to use this version) */
lobyte = s->decode_buffer[lobytes * 2];
hibyte = s->decode_buffer[(lobytes * 2) + 1];
vector_index = ((hibyte << 8) | lobyte) >> 3;
vector_index <<= index_shift;
lines = s->vector_height;
/* uniform color fill - a quick hack */
if (hibyte == 0xFF) {
while (lines--) {
s->frame.data[0][pixel_ptr + 0] = 255 - lobyte;
s->frame.data[0][pixel_ptr + 1] = 255 - lobyte;
s->frame.data[0][pixel_ptr + 2] = 255 - lobyte;
s->frame.data[0][pixel_ptr + 3] = 255 - lobyte;
pixel_ptr += s->frame.linesize[0];
}
lines=0;
}
break;
case 2:
lobyte = s->decode_buffer[lobytes];
hibyte = s->decode_buffer[hibytes];
vector_index = (hibyte << 8) | lobyte;
vector_index <<= index_shift;
lines = s->vector_height;
break;
case 3:
/* not implemented yet */
lines = 0;
break;
}
while (lines--) {
s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++];
s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++];
s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++];
s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++];
pixel_ptr += s->frame.linesize[0];
}
}
}
/* handle partial codebook */
if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
/* a chunk should not have both chunk types */
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBP0 and CBPZ chunks\n");
return;
}
if (cbp0_chunk != -1) {
chunk_size = AV_RB32(&s->buf[cbp0_chunk + 4]);
cbp0_chunk += CHUNK_PREAMBLE_SIZE;
/* accumulate partial codebook */
memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
&s->buf[cbp0_chunk], chunk_size);
s->next_codebook_buffer_index += chunk_size;
s->partial_countdown--;
if (s->partial_countdown == 0) {
/* time to replace codebook */
memcpy(s->codebook, s->next_codebook_buffer,
s->next_codebook_buffer_index);
/* reset accounting */
s->next_codebook_buffer_index = 0;
s->partial_countdown = s->partial_count;
}
}
if (cbpz_chunk != -1) {
chunk_size = AV_RB32(&s->buf[cbpz_chunk + 4]);
cbpz_chunk += CHUNK_PREAMBLE_SIZE;
/* accumulate partial codebook */
memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
&s->buf[cbpz_chunk], chunk_size);
s->next_codebook_buffer_index += chunk_size;
s->partial_countdown--;
if (s->partial_countdown == 0) {
/* decompress codebook */
decode_format80(s->next_codebook_buffer,
s->next_codebook_buffer_index,
s->codebook, s->codebook_size, 0);
/* reset accounting */
s->next_codebook_buffer_index = 0;
s->partial_countdown = s->partial_count;
}
}
}
static int vqa_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
const uint8_t *buf, int buf_size)
{
VqaContext *s = avctx->priv_data;
s->buf = buf;
s->size = buf_size;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
if (avctx->get_buffer(avctx, &s->frame)) {
av_log(s->avctx, AV_LOG_ERROR, " VQA Video: get_buffer() failed\n");
return -1;
}
vqa_decode_chunk(s);
/* make the palette available on the way out */
memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
s->frame.palette_has_changed = 1;
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
/* report that the buffer was completely consumed */
return buf_size;
}
static av_cold int vqa_decode_end(AVCodecContext *avctx)
{
VqaContext *s = avctx->priv_data;
av_free(s->codebook);
av_free(s->next_codebook_buffer);
av_free(s->decode_buffer);
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
return 0;
}
AVCodec vqa_decoder = {
"vqavideo",
CODEC_TYPE_VIDEO,
CODEC_ID_WS_VQA,
sizeof(VqaContext),
vqa_decode_init,
NULL,
vqa_decode_end,
vqa_decode_frame,
CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("Westwood Studios VQA (Vector Quantized Animation) video"),
};
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