/*
* Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
*
* 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
*/
#include "libavutil/intmath.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "avcodec.h"
#include "dsputil.h"
#include "dwt.h"
#include "snow.h"
#include "rangecoder.h"
#include "mathops.h"
#include "mpegvideo.h"
#include "h263.h"
#undef NDEBUG
#include <assert.h>
static av_always_inline void predict_slice_buffered(SnowContext *s, slice_buffer * sb, IDWTELEM * old_buffer, int plane_index, int add, int mb_y){
Plane *p= &s->plane[plane_index];
const int mb_w= s->b_width << s->block_max_depth;
const int mb_h= s->b_height << s->block_max_depth;
int x, y, mb_x;
int block_size = MB_SIZE >> s->block_max_depth;
int block_w = plane_index ? block_size/2 : block_size;
const uint8_t *obmc = plane_index ? obmc_tab[s->block_max_depth+1] : obmc_tab[s->block_max_depth];
int obmc_stride= plane_index ? block_size : 2*block_size;
int ref_stride= s->current_picture.linesize[plane_index];
uint8_t *dst8= s->current_picture.data[plane_index];
int w= p->width;
int h= p->height;
if(s->keyframe || (s->avctx->debug&512)){
if(mb_y==mb_h)
return;
if(add){
for(y=block_w*mb_y; y<FFMIN(h,block_w*(mb_y+1)); y++){
// DWTELEM * line = slice_buffer_get_line(sb, y);
IDWTELEM * line = sb->line[y];
for(x=0; x<w; x++){
// int v= buf[x + y*w] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
int v= line[x] + (128<<FRAC_BITS) + (1<<(FRAC_BITS-1));
v >>= FRAC_BITS;
if(v&(~255)) v= ~(v>>31);
dst8[x + y*ref_stride]= v;
}
}
}else{
for(y=block_w*mb_y; y<FFMIN(h,block_w*(mb_y+1)); y++){
// DWTELEM * line = slice_buffer_get_line(sb, y);
IDWTELEM * line = sb->line[y];
for(x=0; x<w; x++){
line[x] -= 128 << FRAC_BITS;
// buf[x + y*w]-= 128<<FRAC_BITS;
}
}
}
return;
}
for(mb_x=0; mb_x<=mb_w; mb_x++){
add_yblock(s, 1, sb, old_buffer, dst8, obmc,
block_w*mb_x - block_w/2,
block_w*mb_y - block_w/2,
block_w, block_w,
w, h,
w, ref_stride, obmc_stride,
mb_x - 1, mb_y - 1,
add, 0, plane_index);
}
}
static inline void decode_subband_slice_buffered(SnowContext *s, SubBand *b, slice_buffer * sb, int start_y, int h, int save_state[1]){
const int w= b->width;
int y;
const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
int qmul= qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
int new_index = 0;
if(b->ibuf == s->spatial_idwt_buffer || s->qlog == LOSSLESS_QLOG){
qadd= 0;
qmul= 1<<QEXPSHIFT;
}
/* If we are on the second or later slice, restore our index. */
if (start_y != 0)
new_index = save_state[0];
for(y=start_y; y<h; y++){
int x = 0;
int v;
IDWTELEM * line = slice_buffer_get_line(sb, y * b->stride_line + b->buf_y_offset) + b->buf_x_offset;
memset(line, 0, b->width*sizeof(IDWTELEM));
v = b->x_coeff[new_index].coeff;
x = b->x_coeff[new_index++].x;
while(x < w){
register int t= ( (v>>1)*qmul + qadd)>>QEXPSHIFT;
register int u= -(v&1);
line[x] = (t^u) - u;
v = b->x_coeff[new_index].coeff;
x = b->x_coeff[new_index++].x;
}
}
/* Save our variables for the next slice. */
save_state[0] = new_index;
return;
}
static void decode_q_branch(SnowContext *s, int level, int x, int y){
const int w= s->b_width << s->block_max_depth;
const int rem_depth= s->block_max_depth - level;
const int index= (x + y*w) << rem_depth;
int trx= (x+1)<<rem_depth;
const BlockNode *left = x ? &s->block[index-1] : &null_block;
const BlockNode *top = y ? &s->block[index-w] : &null_block;
const BlockNode *tl = y && x ? &s->block[index-w-1] : left;
const BlockNode *tr = y && trx<w && ((x&1)==0 || level==0) ? &s->block[index-w+(1<<rem_depth)] : tl; //FIXME use lt
int s_context= 2*left->level + 2*top->level + tl->level + tr->level;
if(s->keyframe){
set_blocks(s, level, x, y, null_block.color[0], null_block.color[1], null_block.color[2], null_block.mx, null_block.my, null_block.ref, BLOCK_INTRA);
return;
}
if(level==s->block_max_depth || get_rac(&s->c, &s->block_state[4 + s_context])){
int type, mx, my;
int l = left->color[0];
int cb= left->color[1];
int cr= left->color[2];
int ref = 0;
int ref_context= av_log2(2*left->ref) + av_log2(2*top->ref);
int mx_context= av_log2(2*FFABS(left->mx - top->mx)) + 0*av_log2(2*FFABS(tr->mx - top->mx));
int my_context= av_log2(2*FFABS(left->my - top->my)) + 0*av_log2(2*FFABS(tr->my - top->my));
type= get_rac(&s->c, &s->block_state[1 + left->type + top->type]) ? BLOCK_INTRA : 0;
if(type){
pred_mv(s, &mx, &my, 0, left, top, tr);
l += get_symbol(&s->c, &s->block_state[32], 1);
cb+= get_symbol(&s->c, &s->block_state[64], 1);
cr+= get_symbol(&s->c, &s->block_state[96], 1);
}else{
if(s->ref_frames > 1)
ref= get_symbol(&s->c, &s->block_state[128 + 1024 + 32*ref_context], 0);
pred_mv(s, &mx, &my, ref, left, top, tr);
mx+= get_symbol(&s->c, &s->block_state[128 + 32*(mx_context + 16*!!ref)], 1);
my+= get_symbol(&s->c, &s->block_state[128 + 32*(my_context + 16*!!ref)], 1);
}
set_blocks(s, level, x, y, l, cb, cr, mx, my, ref, type);
}else{
decode_q_branch(s, level+1, 2*x+0, 2*y+0);
decode_q_branch(s, level+1, 2*x+1, 2*y+0);
decode_q_branch(s, level+1, 2*x+0, 2*y+1);
decode_q_branch(s, level+1, 2*x+1, 2*y+1);
}
}
static void dequantize_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int start_y, int end_y){
const int w= b->width;
const int qlog= av_clip(s->qlog + b->qlog, 0, QROOT*16);
const int qmul= qexp[qlog&(QROOT-1)]<<(qlog>>QSHIFT);
const int qadd= (s->qbias*qmul)>>QBIAS_SHIFT;
int x,y;
if(s->qlog == LOSSLESS_QLOG) return;
for(y=start_y; y<end_y; y++){
// DWTELEM * line = slice_buffer_get_line_from_address(sb, src + (y * stride));
IDWTELEM * line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
for(x=0; x<w; x++){
int i= line[x];
if(i<0){
line[x]= -((-i*qmul + qadd)>>(QEXPSHIFT)); //FIXME try different bias
}else if(i>0){
line[x]= (( i*qmul + qadd)>>(QEXPSHIFT));
}
}
}
}
static void correlate_slice_buffered(SnowContext *s, slice_buffer * sb, SubBand *b, IDWTELEM *src, int stride, int inverse, int use_median, int start_y, int end_y){
const int w= b->width;
int x,y;
IDWTELEM * line=0; // silence silly "could be used without having been initialized" warning
IDWTELEM * prev;
if (start_y != 0)
line = slice_buffer_get_line(sb, ((start_y - 1) * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
for(y=start_y; y<end_y; y++){
prev = line;
// line = slice_buffer_get_line_from_address(sb, src + (y * stride));
line = slice_buffer_get_line(sb, (y * b->stride_line) + b->buf_y_offset) + b->buf_x_offset;
for(x=0; x<w; x++){
if(x){
if(use_median){
if(y && x+1<w) line[x] += mid_pred(line[x - 1], prev[x], prev[x + 1]);
else line[x] += line[x - 1];
}else{
if(y) line[x] += mid_pred(line[x - 1], prev[x], line[x - 1] + prev[x] - prev[x - 1]);
else line[x] += line[x - 1];
}
}else{
if(y) line[x] += prev[x];
}
}
}
}
static void decode_qlogs(SnowContext *s){
int plane_index, level, orientation;
for(plane_index=0; plane_index<3; plane_index++){
for(level=0; level<s->spatial_decomposition_count; level++){
for(orientation=level ? 1:0; orientation<4; orientation++){
int q;
if (plane_index==2) q= s->plane[1].band[level][orientation].qlog;
else if(orientation==2) q= s->plane[plane_index].band[level][1].qlog;
else q= get_symbol(&s->c, s->header_state, 1);
s->plane[plane_index].band[level][orientation].qlog= q;
}
}
}
}
#define GET_S(dst, check) \
tmp= get_symbol(&s->c, s->header_state, 0);\
if(!(check)){\
av_log(s->avctx, AV_LOG_ERROR, "Error " #dst " is %d\n", tmp);\
return -1;\
}\
dst= tmp;
static int decode_header(SnowContext *s){
int plane_index, tmp;
uint8_t kstate[32];
memset(kstate, MID_STATE, sizeof(kstate));
s->keyframe= get_rac(&s->c, kstate);
if(s->keyframe || s->always_reset){
ff_snow_reset_contexts(s);
s->spatial_decomposition_type=
s->qlog=
s->qbias=
s->mv_scale=
s->block_max_depth= 0;
}
if(s->keyframe){
GET_S(s->version, tmp <= 0U)
s->always_reset= get_rac(&s->c, s->header_state);
s->temporal_decomposition_type= get_symbol(&s->c, s->header_state, 0);
s->temporal_decomposition_count= get_symbol(&s->c, s->header_state, 0);
GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
s->colorspace_type= get_symbol(&s->c, s->header_state, 0);
s->chroma_h_shift= get_symbol(&s->c, s->header_state, 0);
s->chroma_v_shift= get_symbol(&s->c, s->header_state, 0);
s->spatial_scalability= get_rac(&s->c, s->header_state);
// s->rate_scalability= get_rac(&s->c, s->header_state);
GET_S(s->max_ref_frames, tmp < (unsigned)MAX_REF_FRAMES)
s->max_ref_frames++;
decode_qlogs(s);
}
if(!s->keyframe){
if(get_rac(&s->c, s->header_state)){
for(plane_index=0; plane_index<2; plane_index++){
int htaps, i, sum=0;
Plane *p= &s->plane[plane_index];
p->diag_mc= get_rac(&s->c, s->header_state);
htaps= get_symbol(&s->c, s->header_state, 0)*2 + 2;
if((unsigned)htaps > HTAPS_MAX || htaps==0)
return -1;
p->htaps= htaps;
for(i= htaps/2; i; i--){
p->hcoeff[i]= get_symbol(&s->c, s->header_state, 0) * (1-2*(i&1));
sum += p->hcoeff[i];
}
p->hcoeff[0]= 32-sum;
}
s->plane[2].diag_mc= s->plane[1].diag_mc;
s->plane[2].htaps = s->plane[1].htaps;
memcpy(s->plane[2].hcoeff, s->plane[1].hcoeff, sizeof(s->plane[1].hcoeff));
}
if(get_rac(&s->c, s->header_state)){
GET_S(s->spatial_decomposition_count, 0 < tmp && tmp <= MAX_DECOMPOSITIONS)
decode_qlogs(s);
}
}
s->spatial_decomposition_type+= get_symbol(&s->c, s->header_state, 1);
if(s->spatial_decomposition_type > 1U){
av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_type %d not supported", s->spatial_decomposition_type);
return -1;
}
if(FFMIN(s->avctx-> width>>s->chroma_h_shift,
s->avctx->height>>s->chroma_v_shift) >> (s->spatial_decomposition_count-1) <= 0){
av_log(s->avctx, AV_LOG_ERROR, "spatial_decomposition_count %d too large for size", s->spatial_decomposition_count);
return -1;
}
s->qlog += get_symbol(&s->c, s->header_state, 1);
s->mv_scale += get_symbol(&s->c, s->header_state, 1);
s->qbias += get_symbol(&s->c, s->header_state, 1);
s->block_max_depth+= get_symbol(&s->c, s->header_state, 1);
if(s->block_max_depth > 1 || s->block_max_depth < 0){
av_log(s->avctx, AV_LOG_ERROR, "block_max_depth= %d is too large", s->block_max_depth);
s->block_max_depth= 0;
return -1;
}
return 0;
}
static av_cold int decode_init(AVCodecContext *avctx)
{
avctx->pix_fmt= PIX_FMT_YUV420P;
ff_snow_common_init(avctx);
return 0;
}
static void decode_blocks(SnowContext *s){
int x, y;
int w= s->b_width;
int h= s->b_height;
for(y=0; y<h; y++){
for(x=0; x<w; x++){
decode_q_branch(s, 0, x, y);
}
}
}
static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt){
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
SnowContext *s = avctx->priv_data;
RangeCoder * const c= &s->c;
int bytes_read;
AVFrame *picture = data;
int level, orientation, plane_index;
ff_init_range_decoder(c, buf, buf_size);
ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);
s->current_picture.pict_type= AV_PICTURE_TYPE_I; //FIXME I vs. P
if(decode_header(s)<0)
return -1;
ff_snow_common_init_after_header(avctx);
// realloc slice buffer for the case that spatial_decomposition_count changed
ff_slice_buffer_destroy(&s->sb);
ff_slice_buffer_init(&s->sb, s->plane[0].height, (MB_SIZE >> s->block_max_depth) + s->spatial_decomposition_count * 8 + 1, s->plane[0].width, s->spatial_idwt_buffer);
for(plane_index=0; plane_index<3; plane_index++){
Plane *p= &s->plane[plane_index];
p->fast_mc= p->diag_mc && p->htaps==6 && p->hcoeff[0]==40
&& p->hcoeff[1]==-10
&& p->hcoeff[2]==2;
}
ff_snow_alloc_blocks(s);
if(ff_snow_frame_start(s) < 0)
return -1;
//keyframe flag duplication mess FIXME
if(avctx->debug&FF_DEBUG_PICT_INFO)
av_log(avctx, AV_LOG_ERROR, "keyframe:%d qlog:%d\n", s->keyframe, s->qlog);
decode_blocks(s);
for(plane_index=0; plane_index<3; plane_index++){
Plane *p= &s->plane[plane_index];
int w= p->width;
int h= p->height;
int x, y;
int decode_state[MAX_DECOMPOSITIONS][4][1]; /* Stored state info for unpack_coeffs. 1 variable per instance. */
if(s->avctx->debug&2048){
memset(s->spatial_dwt_buffer, 0, sizeof(DWTELEM)*w*h);
predict_plane(s, s->spatial_idwt_buffer, plane_index, 1);
for(y=0; y<h; y++){
for(x=0; x<w; x++){
int v= s->current_picture.data[plane_index][y*s->current_picture.linesize[plane_index] + x];
s->mconly_picture.data[plane_index][y*s->mconly_picture.linesize[plane_index] + x]= v;
}
}
}
{
for(level=0; level<s->spatial_decomposition_count; level++){
for(orientation=level ? 1 : 0; orientation<4; orientation++){
SubBand *b= &p->band[level][orientation];
unpack_coeffs(s, b, b->parent, orientation);
}
}
}
{
const int mb_h= s->b_height << s->block_max_depth;
const int block_size = MB_SIZE >> s->block_max_depth;
const int block_w = plane_index ? block_size/2 : block_size;
int mb_y;
DWTCompose cs[MAX_DECOMPOSITIONS];
int yd=0, yq=0;
int y;
int end_y;
ff_spatial_idwt_buffered_init(cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count);
for(mb_y=0; mb_y<=mb_h; mb_y++){
int slice_starty = block_w*mb_y;
int slice_h = block_w*(mb_y+1);
if (!(s->keyframe || s->avctx->debug&512)){
slice_starty = FFMAX(0, slice_starty - (block_w >> 1));
slice_h -= (block_w >> 1);
}
for(level=0; level<s->spatial_decomposition_count; level++){
for(orientation=level ? 1 : 0; orientation<4; orientation++){
SubBand *b= &p->band[level][orientation];
int start_y;
int end_y;
int our_mb_start = mb_y;
int our_mb_end = (mb_y + 1);
const int extra= 3;
start_y = (mb_y ? ((block_w * our_mb_start) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra: 0);
end_y = (((block_w * our_mb_end) >> (s->spatial_decomposition_count - level)) + s->spatial_decomposition_count - level + extra);
if (!(s->keyframe || s->avctx->debug&512)){
start_y = FFMAX(0, start_y - (block_w >> (1+s->spatial_decomposition_count - level)));
end_y = FFMAX(0, end_y - (block_w >> (1+s->spatial_decomposition_count - level)));
}
start_y = FFMIN(b->height, start_y);
end_y = FFMIN(b->height, end_y);
if (start_y != end_y){
if (orientation == 0){
SubBand * correlate_band = &p->band[0][0];
int correlate_end_y = FFMIN(b->height, end_y + 1);
int correlate_start_y = FFMIN(b->height, (start_y ? start_y + 1 : 0));
decode_subband_slice_buffered(s, correlate_band, &s->sb, correlate_start_y, correlate_end_y, decode_state[0][0]);
correlate_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, 1, 0, correlate_start_y, correlate_end_y);
dequantize_slice_buffered(s, &s->sb, correlate_band, correlate_band->ibuf, correlate_band->stride, start_y, end_y);
}
else
decode_subband_slice_buffered(s, b, &s->sb, start_y, end_y, decode_state[level][orientation]);
}
}
}
for(; yd<slice_h; yd+=4){
ff_spatial_idwt_buffered_slice(&s->dwt, cs, &s->sb, w, h, 1, s->spatial_decomposition_type, s->spatial_decomposition_count, yd);
}
if(s->qlog == LOSSLESS_QLOG){
for(; yq<slice_h && yq<h; yq++){
IDWTELEM * line = slice_buffer_get_line(&s->sb, yq);
for(x=0; x<w; x++){
line[x] <<= FRAC_BITS;
}
}
}
predict_slice_buffered(s, &s->sb, s->spatial_idwt_buffer, plane_index, 1, mb_y);
y = FFMIN(p->height, slice_starty);
end_y = FFMIN(p->height, slice_h);
while(y < end_y)
ff_slice_buffer_release(&s->sb, y++);
}
ff_slice_buffer_flush(&s->sb);
}
}
emms_c();
ff_snow_release_buffer(avctx);
if(!(s->avctx->debug&2048))
*picture= s->current_picture;
else
*picture= s->mconly_picture;
*data_size = sizeof(AVFrame);
bytes_read= c->bytestream - c->bytestream_start;
if(bytes_read ==0) av_log(s->avctx, AV_LOG_ERROR, "error at end of frame\n"); //FIXME
return bytes_read;
}
static av_cold int decode_end(AVCodecContext *avctx)
{
SnowContext *s = avctx->priv_data;
ff_slice_buffer_destroy(&s->sb);
ff_snow_common_end(s);
return 0;
}
AVCodec ff_snow_decoder = {
.name = "snow",
.type = AVMEDIA_TYPE_VIDEO,
.id = CODEC_ID_SNOW,
.priv_data_size = sizeof(SnowContext),
.init = decode_init,
.close = decode_end,
.decode = decode_frame,
.capabilities = CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
.long_name = NULL_IF_CONFIG_SMALL("Snow"),
};