snow: split snow in snowdec and snowenc

The common non inlined code goes in snow.c, the common inlined code in
snow.h, tables move in snowdata.h (included only by snow.c)

1 files changed, 546 insertions, 0 deletions

diff --git a/libavcodec/snowdec.c b/libavcodec/snowdec.c
new file mode 100644
index 0000000000..2b6f6e11c7
--- /dev/null
+++ b/libavcodec/snowdec.c
@@ -0,0 +1,546 @@
+/*
+ * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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"),
+};