224 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			224 lines
		
	
	
		
			7.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 1990 James Ashton - Sydney University
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|  * Copyright (c) 2012 Stefano Sabatini
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| /**
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|  * @file
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|  * X-Face encoder, based on libcompface, by James Ashton.
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|  */
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| 
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| #include "xface.h"
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| #include "avcodec.h"
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| #include "internal.h"
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| #include "libavutil/avassert.h"
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| 
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| typedef struct XFaceContext {
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|     AVClass *class;
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|     uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
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|     int max_line_len;             ///< max line length for compressed data
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|     int set_header;               ///< set X-Face header in the output
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| } XFaceContext;
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| 
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| static int all_same(char *bitmap, int w, int h)
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| {
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|     char val, *row;
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|     int x;
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| 
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|     val = *bitmap;
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|     while (h--) {
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|         row = bitmap;
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|         x = w;
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|         while (x--)
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|             if (*(row++) != val)
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|                 return 0;
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|         bitmap += XFACE_WIDTH;
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|     }
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|     return 1;
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| }
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| 
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| static int all_black(char *bitmap, int w, int h)
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| {
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|     if (w > 3) {
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|         w /= 2;
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|         h /= 2;
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|         return (all_black(bitmap, w, h) && all_black(bitmap + w, w, h) &&
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|                 all_black(bitmap + XFACE_WIDTH * h, w, h) &&
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|                 all_black(bitmap + XFACE_WIDTH * h + w, w, h));
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|     } else {
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|         /* at least one pixel in the 2x2 grid is non-zero */
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|         return *bitmap || *(bitmap + 1) ||
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|                *(bitmap + XFACE_WIDTH) || *(bitmap + XFACE_WIDTH + 1);
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|     }
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| }
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| 
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| static int all_white(char *bitmap, int w, int h)
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| {
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|     return *bitmap == 0 && all_same(bitmap, w, h);
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| }
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| 
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| typedef struct {
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|     ProbRange prob_ranges[XFACE_PIXELS*2];
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|     int prob_ranges_idx;
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| } ProbRangesQueue;
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| 
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| static inline int pq_push(ProbRangesQueue *pq, const ProbRange *p)
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| {
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|     if (pq->prob_ranges_idx >= XFACE_PIXELS * 2 - 1)
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|         return -1;
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|     pq->prob_ranges[pq->prob_ranges_idx++] = *p;
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|     return 0;
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| }
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| 
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| static void push_greys(ProbRangesQueue *pq, char *bitmap, int w, int h)
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| {
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|     if (w > 3) {
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|         w /= 2;
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|         h /= 2;
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|         push_greys(pq, bitmap,                       w, h);
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|         push_greys(pq, bitmap + w,                   w, h);
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|         push_greys(pq, bitmap + XFACE_WIDTH * h,     w, h);
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|         push_greys(pq, bitmap + XFACE_WIDTH * h + w, w, h);
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|     } else {
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|         const ProbRange *p = ff_xface_probranges_2x2 +
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|                  *bitmap +
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|             2 * *(bitmap + 1) +
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|             4 * *(bitmap + XFACE_WIDTH) +
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|             8 * *(bitmap + XFACE_WIDTH + 1);
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|         pq_push(pq, p);
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|     }
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| }
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| 
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| static void encode_block(char *bitmap, int w, int h, int level, ProbRangesQueue *pq)
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| {
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|     if (all_white(bitmap, w, h)) {
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|         pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_WHITE]);
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|     } else if (all_black(bitmap, w, h)) {
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|         pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_BLACK]);
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|         push_greys(pq, bitmap, w, h);
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|     } else {
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|         pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_GREY]);
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|         w /= 2;
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|         h /= 2;
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|         level++;
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|         encode_block(bitmap,                       w, h, level, pq);
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|         encode_block(bitmap + w,                   w, h, level, pq);
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|         encode_block(bitmap + h * XFACE_WIDTH,     w, h, level, pq);
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|         encode_block(bitmap + w + h * XFACE_WIDTH, w, h, level, pq);
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|     }
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| }
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| 
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| static void push_integer(BigInt *b, const ProbRange *prange)
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| {
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|     uint8_t r;
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| 
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|     ff_big_div(b, prange->range, &r);
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|     ff_big_mul(b, 0);
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|     ff_big_add(b, r + prange->offset);
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| }
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| 
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| static int xface_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
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|                               const AVFrame *frame, int *got_packet)
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| {
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|     XFaceContext *xface = avctx->priv_data;
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|     ProbRangesQueue pq = {{{ 0 }}, 0};
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|     uint8_t bitmap_copy[XFACE_PIXELS];
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|     BigInt b = {0};
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|     int i, j, k, ret = 0;
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|     const uint8_t *buf;
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|     uint8_t *p;
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|     char intbuf[XFACE_MAX_DIGITS];
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| 
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|     if (avctx->width || avctx->height) {
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|         if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
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|             av_log(avctx, AV_LOG_ERROR,
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|                    "Size value %dx%d not supported, only accepts a size of %dx%d\n",
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|                    avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
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|             return AVERROR(EINVAL);
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|         }
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|     }
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|     avctx->width  = XFACE_WIDTH;
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|     avctx->height = XFACE_HEIGHT;
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| 
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|     /* convert image from MONOWHITE to 1=black 0=white bitmap */
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|     buf = frame->data[0];
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|     i = j = 0;
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|     do {
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|         for (k = 0; k < 8; k++)
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|             xface->bitmap[i++] = (buf[j]>>(7-k))&1;
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|         if (++j == XFACE_WIDTH/8) {
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|             buf += frame->linesize[0];
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|             j = 0;
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|         }
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|     } while (i < XFACE_PIXELS);
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| 
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|     /* create a copy of bitmap */
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|     memcpy(bitmap_copy, xface->bitmap, XFACE_PIXELS);
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|     ff_xface_generate_face(xface->bitmap, bitmap_copy);
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| 
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|     encode_block(xface->bitmap,                         16, 16, 0, &pq);
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|     encode_block(xface->bitmap + 16,                    16, 16, 0, &pq);
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|     encode_block(xface->bitmap + 32,                    16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 16,      16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 16 + 16, 16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 16 + 32, 16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 32,      16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 32 + 16, 16, 16, 0, &pq);
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|     encode_block(xface->bitmap + XFACE_WIDTH * 32 + 32, 16, 16, 0, &pq);
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| 
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|     while (pq.prob_ranges_idx > 0)
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|         push_integer(&b, &pq.prob_ranges[--pq.prob_ranges_idx]);
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| 
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|     /* write the inverted big integer in b to intbuf */
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|     i = 0;
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|     av_assert0(b.nb_words < XFACE_MAX_WORDS);
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|     while (b.nb_words) {
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|         uint8_t r;
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|         ff_big_div(&b, XFACE_PRINTS, &r);
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|         av_assert0(i < sizeof(intbuf));
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|         intbuf[i++] = r + XFACE_FIRST_PRINT;
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|     }
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| 
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|     if ((ret = ff_alloc_packet2(avctx, pkt, i+2, 0)) < 0)
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|         return ret;
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| 
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|     /* revert the number, and close the buffer */
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|     p = pkt->data;
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|     while (--i >= 0)
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|         *(p++) = intbuf[i];
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|     *(p++) = '\n';
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|     *(p++) = 0;
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| 
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|     pkt->flags |= AV_PKT_FLAG_KEY;
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|     *got_packet = 1;
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| 
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|     return 0;
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| }
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| 
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| AVCodec ff_xface_encoder = {
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|     .name           = "xface",
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|     .long_name      = NULL_IF_CONFIG_SMALL("X-face image"),
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|     .type           = AVMEDIA_TYPE_VIDEO,
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|     .id             = AV_CODEC_ID_XFACE,
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|     .priv_data_size = sizeof(XFaceContext),
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|     .encode2        = xface_encode_frame,
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|     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
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|     .capabilities   = AV_CODEC_CAP_INTRA_ONLY,
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| };
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