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FFmpeg/libavcodec/vqavideo.c
Reinhard Tartler 737eb5976f Merge libavcore into libavutil 
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
2011-02-15 16:18:21 +01:00

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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
* 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 "libavutil/intreadwrite.h"
#include "libavutil/imgutils.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(av_image_check_size(s->width, s->height, 0, avctx)){
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,
AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->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 ff_vqa_decoder = {
"vqavideo",
AVMEDIA_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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