/*
* 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
* @author Mike Melanson (melanson@pcisys.net)
* @see 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"
#include "bytestream.h"
#include "internal.h"
#define PALETTE_COUNT 256
#define VQA_HEADER_SIZE 0x2A
/* 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')
typedef struct VqaContext {
AVCodecContext *avctx;
GetByteContext gb;
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;
int i, j, codebook_index, ret;
s->avctx = avctx;
avctx->pix_fmt = AV_PIX_FMT_PAL8;
/* make sure the extradata made it */
if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
av_log(s->avctx, AV_LOG_ERROR, "expected extradata size of %d\n", VQA_HEADER_SIZE);
return AVERROR(EINVAL);
}
/* load up the VQA parameters from the header */
s->vqa_version = s->avctx->extradata[0];
switch (s->vqa_version) {
case 1:
case 2:
break;
case 3:
avpriv_report_missing_feature(avctx, "VQA Version %d", s->vqa_version);
return AVERROR_PATCHWELCOME;
default:
avpriv_request_sample(avctx, "VQA Version %i", s->vqa_version);
return AVERROR_PATCHWELCOME;
}
s->width = AV_RL16(&s->avctx->extradata[6]);
s->height = AV_RL16(&s->avctx->extradata[8]);
if ((ret = av_image_check_size(s->width, s->height, 0, avctx)) < 0) {
s->width= s->height= 0;
return ret;
}
s->vector_width = s->avctx->extradata[10];
s->vector_height = s->avctx->extradata[11];
s->partial_count = s->partial_countdown = s->avctx->extradata[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 AVERROR_INVALIDDATA;
}
if (s->width % s->vector_width || s->height % s->vector_height) {
av_log(avctx, AV_LOG_ERROR, "Image size not multiple of block size\n");
return AVERROR_INVALIDDATA;
}
/* allocate codebooks */
s->codebook_size = MAX_CODEBOOK_SIZE;
s->codebook = av_malloc(s->codebook_size);
if (!s->codebook)
goto fail;
s->next_codebook_buffer = av_malloc(s->codebook_size);
if (!s->next_codebook_buffer)
goto fail;
/* allocate decode buffer */
s->decode_buffer_size = (s->width / s->vector_width) *
(s->height / s->vector_height) * 2;
s->decode_buffer = av_mallocz(s->decode_buffer_size);
if (!s->decode_buffer)
goto fail;
/* 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;
return 0;
fail:
av_freep(&s->codebook);
av_freep(&s->next_codebook_buffer);
av_freep(&s->decode_buffer);
return AVERROR(ENOMEM);
}
#define CHECK_COUNT() \
if (dest_index + count > dest_size) { \
av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
av_log(s->avctx, AV_LOG_ERROR, "current dest_index = %d, count = %d, dest_size = %d\n", \
dest_index, count, dest_size); \
return AVERROR_INVALIDDATA; \
}
#define CHECK_COPY(idx) \
if (idx < 0 || idx + count > dest_size) { \
av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: next op would overflow dest_index\n"); \
av_log(s->avctx, AV_LOG_ERROR, "current src_pos = %d, count = %d, dest_size = %d\n", \
src_pos, count, dest_size); \
return AVERROR_INVALIDDATA; \
}
static int decode_format80(VqaContext *s, int src_size,
unsigned char *dest, int dest_size, int check_size) {
int dest_index = 0;
int count, opcode, start;
int src_pos;
unsigned char color;
int i;
if (src_size < 0 || src_size > bytestream2_get_bytes_left(&s->gb)) {
av_log(s->avctx, AV_LOG_ERROR, "Chunk size %d is out of range\n",
src_size);
return AVERROR_INVALIDDATA;
}
start = bytestream2_tell(&s->gb);
while (bytestream2_tell(&s->gb) - start < src_size) {
opcode = bytestream2_get_byte(&s->gb);
ff_tlog(s->avctx, "opcode %02X: ", opcode);
/* 0x80 means that frame is finished */
if (opcode == 0x80)
break;
if (dest_index >= dest_size) {
av_log(s->avctx, AV_LOG_ERROR, "decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
dest_index, dest_size);
return AVERROR_INVALIDDATA;
}
if (opcode == 0xFF) {
count = bytestream2_get_le16(&s->gb);
src_pos = bytestream2_get_le16(&s->gb);
ff_tlog(s->avctx, "(1) copy %X bytes from absolute pos %X\n", count, src_pos);
CHECK_COUNT();
CHECK_COPY(src_pos);
for (i = 0; i < count; i++)
dest[dest_index + i] = dest[src_pos + i];
dest_index += count;
} else if (opcode == 0xFE) {
count = bytestream2_get_le16(&s->gb);
color = bytestream2_get_byte(&s->gb);
ff_tlog(s->avctx, "(2) set %X bytes to %02X\n", count, color);
CHECK_COUNT();
memset(&dest[dest_index], color, count);
dest_index += count;
} else if ((opcode & 0xC0) == 0xC0) {
count = (opcode & 0x3F) + 3;
src_pos = bytestream2_get_le16(&s->gb);
ff_tlog(s->avctx, "(3) copy %X bytes from absolute pos %X\n", count, src_pos);
CHECK_COUNT();
CHECK_COPY(src_pos);
for (i = 0; i < count; i++)
dest[dest_index + i] = dest[src_pos + i];
dest_index += count;
} else if (opcode > 0x80) {
count = opcode & 0x3F;
ff_tlog(s->avctx, "(4) copy %X bytes from source to dest\n", count);
CHECK_COUNT();
bytestream2_get_buffer(&s->gb, &dest[dest_index], count);
dest_index += count;
} else {
count = ((opcode & 0x70) >> 4) + 3;
src_pos = bytestream2_get_byte(&s->gb) | ((opcode & 0x0F) << 8);
ff_tlog(s->avctx, "(5) copy %X bytes from relpos %X\n", count, src_pos);
CHECK_COUNT();
CHECK_COPY(dest_index - src_pos);
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(s->avctx, AV_LOG_ERROR, "decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
dest_index, dest_size);
memset(dest + dest_index, 0, dest_size - dest_index);
}
return 0; // let's display what we decoded anyway
}
static int vqa_decode_chunk(VqaContext *s, AVFrame *frame)
{
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 res;
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 (bytestream2_get_bytes_left(&s->gb) >= 8) {
chunk_type = bytestream2_get_be32u(&s->gb);
index = bytestream2_tell(&s->gb);
chunk_size = bytestream2_get_be32u(&s->gb);
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, "Found unknown chunk type: %s (%08X)\n",
av_fourcc2str(av_bswap32(chunk_type)), chunk_type);
break;
}
byte_skip = chunk_size & 0x01;
bytestream2_skip(&s->gb, 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, "problem: found both CPL0 and CPLZ chunks\n");
return AVERROR_INVALIDDATA;
}
/* 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) {
bytestream2_seek(&s->gb, cpl0_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
/* sanity check the palette size */
if (chunk_size / 3 > 256 || chunk_size > bytestream2_get_bytes_left(&s->gb)) {
av_log(s->avctx, AV_LOG_ERROR, "problem: found a palette chunk with %d colors\n",
chunk_size / 3);
return AVERROR_INVALIDDATA;
}
for (i = 0; i < chunk_size / 3; i++) {
/* scale by 4 to transform 6-bit palette -> 8-bit */
r = bytestream2_get_byteu(&s->gb) * 4;
g = bytestream2_get_byteu(&s->gb) * 4;
b = bytestream2_get_byteu(&s->gb) * 4;
s->palette[i] = 0xFFU << 24 | r << 16 | g << 8 | b;
s->palette[i] |= s->palette[i] >> 6 & 0x30303;
}
}
/* 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, "problem: found both CBF0 and CBFZ chunks\n");
return AVERROR_INVALIDDATA;
}
/* decompress the full codebook chunk */
if (cbfz_chunk != -1) {
bytestream2_seek(&s->gb, cbfz_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
if ((res = decode_format80(s, chunk_size, s->codebook,
s->codebook_size, 0)) < 0)
return res;
}
/* copy a full codebook */
if (cbf0_chunk != -1) {
bytestream2_seek(&s->gb, cbf0_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
/* sanity check the full codebook size */
if (chunk_size > MAX_CODEBOOK_SIZE) {
av_log(s->avctx, AV_LOG_ERROR, "problem: CBF0 chunk too large (0x%X bytes)\n",
chunk_size);
return AVERROR_INVALIDDATA;
}
bytestream2_get_buffer(&s->gb, s->codebook, 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, "problem: no VPTZ chunk found\n");
return AVERROR_INVALIDDATA;
}
bytestream2_seek(&s->gb, vptz_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
if ((res = decode_format80(s, chunk_size,
s->decode_buffer, s->decode_buffer_size, 1)) < 0)
return res;
/* render the final PAL8 frame */
if (s->vector_height == 4)
index_shift = 4;
else
index_shift = 3;
for (y = 0; y < s->height; y += s->vector_height) {
for (x = 0; x < s->width; x += 4, lobytes++, hibytes++) {
pixel_ptr = y * frame->linesize[0] + x;
/* get the vector index, the method for which varies according to
* VQA file version */
switch (s->vqa_version) {
case 1:
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--) {
frame->data[0][pixel_ptr + 0] = 255 - lobyte;
frame->data[0][pixel_ptr + 1] = 255 - lobyte;
frame->data[0][pixel_ptr + 2] = 255 - lobyte;
frame->data[0][pixel_ptr + 3] = 255 - lobyte;
pixel_ptr += 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--) {
frame->data[0][pixel_ptr + 0] = s->codebook[vector_index++];
frame->data[0][pixel_ptr + 1] = s->codebook[vector_index++];
frame->data[0][pixel_ptr + 2] = s->codebook[vector_index++];
frame->data[0][pixel_ptr + 3] = s->codebook[vector_index++];
pixel_ptr += 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, "problem: found both CBP0 and CBPZ chunks\n");
return AVERROR_INVALIDDATA;
}
if (cbp0_chunk != -1) {
bytestream2_seek(&s->gb, cbp0_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
av_log(s->avctx, AV_LOG_ERROR, "cbp0 chunk too large (%u bytes)\n",
chunk_size);
return AVERROR_INVALIDDATA;
}
/* accumulate partial codebook */
bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index],
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) {
bytestream2_seek(&s->gb, cbpz_chunk, SEEK_SET);
chunk_size = bytestream2_get_be32(&s->gb);
if (chunk_size > MAX_CODEBOOK_SIZE - s->next_codebook_buffer_index) {
av_log(s->avctx, AV_LOG_ERROR, "cbpz chunk too large (%u bytes)\n",
chunk_size);
return AVERROR_INVALIDDATA;
}
/* accumulate partial codebook */
bytestream2_get_buffer(&s->gb, &s->next_codebook_buffer[s->next_codebook_buffer_index],
chunk_size);
s->next_codebook_buffer_index += chunk_size;
s->partial_countdown--;
if (s->partial_countdown <= 0) {
bytestream2_init(&s->gb, s->next_codebook_buffer, s->next_codebook_buffer_index);
/* decompress codebook */
if ((res = decode_format80(s, s->next_codebook_buffer_index,
s->codebook, s->codebook_size, 0)) < 0)
return res;
/* reset accounting */
s->next_codebook_buffer_index = 0;
s->partial_countdown = s->partial_count;
}
}
return 0;
}
static int vqa_decode_frame(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
{
VqaContext *s = avctx->priv_data;
AVFrame *frame = data;
int res;
if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
return res;
bytestream2_init(&s->gb, avpkt->data, avpkt->size);
if ((res = vqa_decode_chunk(s, frame)) < 0)
return res;
/* make the palette available on the way out */
memcpy(frame->data[1], s->palette, PALETTE_COUNT * 4);
frame->palette_has_changed = 1;
*got_frame = 1;
/* report that the buffer was completely consumed */
return avpkt->size;
}
static av_cold int vqa_decode_end(AVCodecContext *avctx)
{
VqaContext *s = avctx->priv_data;
av_freep(&s->codebook);
av_freep(&s->next_codebook_buffer);
av_freep(&s->decode_buffer);
return 0;
}
AVCodec ff_vqa_decoder = {
.name = "vqavideo",
.long_name = NULL_IF_CONFIG_SMALL("Westwood Studios VQA (Vector Quantized Animation) video"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_WS_VQA,
.priv_data_size = sizeof(VqaContext),
.init = vqa_decode_init,
.close = vqa_decode_end,
.decode = vqa_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};