ffmpeg/libavcodec/fraps.c

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/*
* Fraps FPS1 decoder
* Copyright (c) 2005 Roine Gustafsson
* Copyright (c) 2006 Konstantin Shishkov
*
* 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 fraps.c
* Lossless Fraps 'FPS1' decoder
* @author Roine Gustafsson <roine at users sf net>
* @author Konstantin Shishkov
*
* Codec algorithm for version 0 is taken from Transcode <www.transcoding.org>
*
* Version 2 files support by Konstantin Shishkov
*/
#include "avcodec.h"
#include "bitstream.h"
#include "dsputil.h"
#define FPS_TAG MKTAG('F', 'P', 'S', 'x')
/* symbol for Huffman tree node */
#define HNODE -1
/**
* Huffman node
* FIXME one day this should belong to one general framework
*/
typedef struct Node{
int16_t sym;
int16_t n0;
int count;
}Node;
/**
* local variable storage
*/
typedef struct FrapsContext{
AVCodecContext *avctx;
AVFrame frame;
Node nodes[512];
uint8_t *tmpbuf;
DSPContext dsp;
} FrapsContext;
/**
* initializes decoder
* @param avctx codec context
* @return 0 on success or negative if fails
*/
static int decode_init(AVCodecContext *avctx)
{
FrapsContext * const s = avctx->priv_data;
avctx->coded_frame = (AVFrame*)&s->frame;
avctx->has_b_frames = 0;
avctx->pix_fmt= PIX_FMT_NONE; /* set in decode_frame */
s->avctx = avctx;
s->frame.data[0] = NULL;
s->tmpbuf = NULL;
dsputil_init(&s->dsp, avctx);
return 0;
}
/**
* Comparator - our nodes should ascend by count
* but with preserved symbol order
*/
static int huff_cmp(const Node *a, const Node *b){
return (a->count - b->count)*256 + a->sym - b->sym;
}
static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *nodes, int node, uint32_t pfx, int pl, int *pos)
{
int s;
s = nodes[node].sym;
if(s != HNODE || !nodes[node].count){
bits[*pos] = pfx;
lens[*pos] = pl;
xlat[*pos] = s;
(*pos)++;
}else{
pfx <<= 1;
pl++;
get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl, pos);
pfx |= 1;
get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0+1, pfx, pl, pos);
}
}
static int build_huff_tree(VLC *vlc, Node *nodes, uint8_t *xlat)
{
uint32_t bits[256];
int16_t lens[256];
int pos = 0;
get_tree_codes(bits, lens, xlat, nodes, 510, 0, 0, &pos);
return init_vlc(vlc, 9, pos, lens, 2, 2, bits, 4, 4, 0);
}
/**
* decode Fraps v2 packed plane
*/
static int fraps2_decode_plane(FrapsContext *s, uint8_t *dst, int stride, int w,
int h, uint8_t *src, int size, int Uoff)
{
int i, j;
int cur_node;
GetBitContext gb;
VLC vlc;
int64_t sum = 0;
uint8_t recode[256];
for(i = 0; i < 256; i++){
s->nodes[i].sym = i;
s->nodes[i].count = LE_32(src);
s->nodes[i].n0 = -2;
if(s->nodes[i].count < 0) {
av_log(s->avctx, AV_LOG_ERROR, "Symbol count < 0\n");
return -1;
}
src += 4;
sum += s->nodes[i].count;
}
size -= 1024;
if(sum >> 31) {
av_log(s->avctx, AV_LOG_ERROR, "Too high symbol frequencies. Tree construction is not possible\n");
return -1;
}
qsort(s->nodes, 256, sizeof(Node), huff_cmp);
cur_node = 256;
for(i = 0; i < 511; i += 2){
s->nodes[cur_node].sym = HNODE;
s->nodes[cur_node].count = s->nodes[i].count + s->nodes[i+1].count;
s->nodes[cur_node].n0 = i;
for(j = cur_node; j > 0; j--){
if(s->nodes[j].count >= s->nodes[j - 1].count) break;
FFSWAP(Node, s->nodes[j], s->nodes[j - 1]);
}
cur_node++;
}
if(build_huff_tree(&vlc, s->nodes, recode) < 0){
av_log(s->avctx, AV_LOG_ERROR, "Error building tree\n");
return -1;
}
/* we have built Huffman table and are ready to decode plane */
/* convert bits so they may be used by standard bitreader */
s->dsp.bswap_buf(s->tmpbuf, src, size >> 2);
init_get_bits(&gb, s->tmpbuf, size * 8);
for(j = 0; j < h; j++){
for(i = 0; i < w; i++){
dst[i] = recode[get_vlc2(&gb, vlc.table, 9, 3)];
/* lines are stored as deltas between previous lines
* and we need to add 0x80 to the first lines of chroma planes
*/
if(j) dst[i] += dst[i - stride];
else if(Uoff) dst[i] += 0x80;
}
dst += stride;
}
free_vlc(&vlc);
return 0;
}
/**
* decode a frame
* @param avctx codec context
* @param data output AVFrame
* @param data_size size of output data or 0 if no picture is returned
* @param buf input data frame
* @param buf_size size of input data frame
* @return number of consumed bytes on success or negative if decode fails
*/
static int decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
FrapsContext * const s = avctx->priv_data;
AVFrame *frame = data;
AVFrame * const f = (AVFrame*)&s->frame;
uint32_t header;
unsigned int version,header_size;
unsigned int x, y;
uint32_t *buf32;
uint32_t *luma1,*luma2,*cb,*cr;
uint32_t offs[4];
int i, is_chroma, planes;
header = LE_32(buf);
version = header & 0xff;
header_size = (header & (1<<30))? 8 : 4; /* bit 30 means pad to 8 bytes */
if (version > 2 && version != 4) {
av_log(avctx, AV_LOG_ERROR,
"This file is encoded with Fraps version %d. " \
"This codec can only decode version 0, 1, 2 and 4.\n", version);
return -1;
}
buf+=4;
if (header_size == 8)
buf+=4;
switch(version) {
case 0:
default:
/* Fraps v0 is a reordered YUV420 */
avctx->pix_fmt = PIX_FMT_YUV420P;
if ( (buf_size != avctx->width*avctx->height*3/2+header_size) &&
(buf_size != header_size) ) {
av_log(avctx, AV_LOG_ERROR,
"Invalid frame length %d (should be %d)\n",
buf_size, avctx->width*avctx->height*3/2+header_size);
return -1;
}
if (( (avctx->width % 8) != 0) || ( (avctx->height % 2) != 0 )) {
av_log(avctx, AV_LOG_ERROR, "Invalid frame size %dx%d\n",
avctx->width, avctx->height);
return -1;
}
f->reference = 1;
f->buffer_hints = FF_BUFFER_HINTS_VALID |
FF_BUFFER_HINTS_PRESERVE |
FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, f)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
/* bit 31 means same as previous pic */
f->pict_type = (header & (1<<31))? FF_P_TYPE : FF_I_TYPE;
f->key_frame = f->pict_type == FF_I_TYPE;
if (f->pict_type == FF_I_TYPE) {
buf32=(uint32_t*)buf;
for(y=0; y<avctx->height/2; y++){
luma1=(uint32_t*)&f->data[0][ y*2*f->linesize[0] ];
luma2=(uint32_t*)&f->data[0][ (y*2+1)*f->linesize[0] ];
cr=(uint32_t*)&f->data[1][ y*f->linesize[1] ];
cb=(uint32_t*)&f->data[2][ y*f->linesize[2] ];
for(x=0; x<avctx->width; x+=8){
*(luma1++) = *(buf32++);
*(luma1++) = *(buf32++);
*(luma2++) = *(buf32++);
*(luma2++) = *(buf32++);
*(cr++) = *(buf32++);
*(cb++) = *(buf32++);
}
}
}
break;
case 1:
/* Fraps v1 is an upside-down BGR24 */
avctx->pix_fmt = PIX_FMT_BGR24;
if ( (buf_size != avctx->width*avctx->height*3+header_size) &&
(buf_size != header_size) ) {
av_log(avctx, AV_LOG_ERROR,
"Invalid frame length %d (should be %d)\n",
buf_size, avctx->width*avctx->height*3+header_size);
return -1;
}
f->reference = 1;
f->buffer_hints = FF_BUFFER_HINTS_VALID |
FF_BUFFER_HINTS_PRESERVE |
FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, f)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
/* bit 31 means same as previous pic */
f->pict_type = (header & (1<<31))? FF_P_TYPE : FF_I_TYPE;
f->key_frame = f->pict_type == FF_I_TYPE;
if (f->pict_type == FF_I_TYPE) {
for(y=0; y<avctx->height; y++)
memcpy(&f->data[0][ (avctx->height-y)*f->linesize[0] ],
&buf[y*avctx->width*3],
f->linesize[0]);
}
break;
case 2:
case 4:
/**
* Fraps v2 is Huffman-coded YUV420 planes
* Fraps v4 is virtually the same
*/
avctx->pix_fmt = PIX_FMT_YUV420P;
planes = 3;
f->reference = 1;
f->buffer_hints = FF_BUFFER_HINTS_VALID |
FF_BUFFER_HINTS_PRESERVE |
FF_BUFFER_HINTS_REUSABLE;
if (avctx->reget_buffer(avctx, f)) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
return -1;
}
/* skip frame */
if(buf_size == 8) {
f->pict_type = FF_P_TYPE;
f->key_frame = 0;
break;
}
f->pict_type = FF_I_TYPE;
f->key_frame = 1;
if ((LE_32(buf) != FPS_TAG)||(buf_size < (planes*1024 + 24))) {
av_log(avctx, AV_LOG_ERROR, "Fraps: error in data stream\n");
return -1;
}
for(i = 0; i < planes; i++) {
offs[i] = LE_32(buf + 4 + i * 4);
if(offs[i] >= buf_size || (i && offs[i] <= offs[i - 1] + 1024)) {
av_log(avctx, AV_LOG_ERROR, "Fraps: plane %i offset is out of bounds\n", i);
return -1;
}
}
offs[planes] = buf_size;
for(i = 0; i < planes; i++){
is_chroma = !!i;
s->tmpbuf = av_realloc(s->tmpbuf, offs[i + 1] - offs[i] - 1024 + FF_INPUT_BUFFER_PADDING_SIZE);
if(fraps2_decode_plane(s, f->data[i], f->linesize[i], avctx->width >> is_chroma,
avctx->height >> is_chroma, buf + offs[i], offs[i + 1] - offs[i], is_chroma) < 0) {
av_log(avctx, AV_LOG_ERROR, "Error decoding plane %i\n", i);
return -1;
}
}
break;
}
*frame = *f;
*data_size = sizeof(AVFrame);
return buf_size;
}
/**
* closes decoder
* @param avctx codec context
* @return 0 on success or negative if fails
*/
static int decode_end(AVCodecContext *avctx)
{
FrapsContext *s = (FrapsContext*)avctx->priv_data;
if (s->frame.data[0])
avctx->release_buffer(avctx, &s->frame);
av_freep(&s->tmpbuf);
return 0;
}
AVCodec fraps_decoder = {
"fraps",
CODEC_TYPE_VIDEO,
CODEC_ID_FRAPS,
sizeof(FrapsContext),
decode_init,
NULL,
decode_end,
decode_frame,
CODEC_CAP_DR1,
};