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325 lines
9.5 KiB
325 lines
9.5 KiB
/* |
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* QPEG codec |
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* Copyright (c) 2004 Konstantin Shishkov |
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* |
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* This file is part of Libav. |
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* |
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* Libav 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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* Libav 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 Libav; 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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* @file |
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* QPEG codec. |
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*/ |
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#include "avcodec.h" |
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typedef struct QpegContext{ |
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AVCodecContext *avctx; |
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AVFrame pic; |
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uint8_t *refdata; |
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} QpegContext; |
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static void qpeg_decode_intra(const uint8_t *src, uint8_t *dst, int size, |
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int stride, int width, int height) |
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{ |
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int i; |
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int code; |
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int c0, c1; |
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int run, copy; |
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int filled = 0; |
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int rows_to_go; |
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rows_to_go = height; |
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height--; |
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dst = dst + height * stride; |
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while((size > 0) && (rows_to_go > 0)) { |
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code = *src++; |
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size--; |
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run = copy = 0; |
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if(code == 0xFC) /* end-of-picture code */ |
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break; |
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if(code >= 0xF8) { /* very long run */ |
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c0 = *src++; |
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c1 = *src++; |
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size -= 2; |
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run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2; |
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} else if (code >= 0xF0) { /* long run */ |
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c0 = *src++; |
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size--; |
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run = ((code & 0xF) << 8) + c0 + 2; |
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} else if (code >= 0xE0) { /* short run */ |
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run = (code & 0x1F) + 2; |
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} else if (code >= 0xC0) { /* very long copy */ |
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c0 = *src++; |
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c1 = *src++; |
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size -= 2; |
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copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1; |
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} else if (code >= 0x80) { /* long copy */ |
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c0 = *src++; |
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size--; |
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copy = ((code & 0x7F) << 8) + c0 + 1; |
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} else { /* short copy */ |
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copy = code + 1; |
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} |
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/* perform actual run or copy */ |
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if(run) { |
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int p; |
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p = *src++; |
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size--; |
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for(i = 0; i < run; i++) { |
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dst[filled++] = p; |
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if (filled >= width) { |
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filled = 0; |
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dst -= stride; |
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rows_to_go--; |
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if(rows_to_go <= 0) |
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break; |
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} |
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} |
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} else { |
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size -= copy; |
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for(i = 0; i < copy; i++) { |
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dst[filled++] = *src++; |
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if (filled >= width) { |
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filled = 0; |
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dst -= stride; |
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rows_to_go--; |
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if(rows_to_go <= 0) |
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break; |
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} |
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} |
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} |
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} |
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} |
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static const int qpeg_table_h[16] = |
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{ 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04}; |
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static const int qpeg_table_w[16] = |
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{ 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04}; |
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/* Decodes delta frames */ |
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static void qpeg_decode_inter(const uint8_t *src, uint8_t *dst, int size, |
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int stride, int width, int height, |
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int delta, const uint8_t *ctable, uint8_t *refdata) |
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{ |
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int i, j; |
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int code; |
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int filled = 0; |
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int orig_height; |
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/* copy prev frame */ |
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for(i = 0; i < height; i++) |
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memcpy(refdata + (i * width), dst + (i * stride), width); |
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orig_height = height; |
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height--; |
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dst = dst + height * stride; |
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while((size > 0) && (height >= 0)) { |
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code = *src++; |
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size--; |
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if(delta) { |
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/* motion compensation */ |
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while((code & 0xF0) == 0xF0) { |
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if(delta == 1) { |
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int me_idx; |
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int me_w, me_h, me_x, me_y; |
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uint8_t *me_plane; |
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int corr, val; |
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/* get block size by index */ |
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me_idx = code & 0xF; |
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me_w = qpeg_table_w[me_idx]; |
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me_h = qpeg_table_h[me_idx]; |
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/* extract motion vector */ |
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corr = *src++; |
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size--; |
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val = corr >> 4; |
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if(val > 7) |
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val -= 16; |
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me_x = val; |
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val = corr & 0xF; |
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if(val > 7) |
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val -= 16; |
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me_y = val; |
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/* check motion vector */ |
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if ((me_x + filled < 0) || (me_x + me_w + filled > width) || |
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(height - me_y - me_h < 0) || (height - me_y > orig_height) || |
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(filled + me_w > width) || (height - me_h < 0)) |
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av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n", |
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me_x, me_y, me_w, me_h, filled, height); |
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else { |
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/* do motion compensation */ |
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me_plane = refdata + (filled + me_x) + (height - me_y) * width; |
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for(j = 0; j < me_h; j++) { |
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for(i = 0; i < me_w; i++) |
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dst[filled + i - (j * stride)] = me_plane[i - (j * width)]; |
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} |
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} |
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} |
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code = *src++; |
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size--; |
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} |
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} |
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if(code == 0xE0) /* end-of-picture code */ |
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break; |
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if(code > 0xE0) { /* run code: 0xE1..0xFF */ |
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int p; |
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code &= 0x1F; |
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p = *src++; |
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size--; |
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for(i = 0; i <= code; i++) { |
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dst[filled++] = p; |
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if(filled >= width) { |
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filled = 0; |
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dst -= stride; |
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height--; |
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} |
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} |
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} else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */ |
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code &= 0x1F; |
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for(i = 0; i <= code; i++) { |
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dst[filled++] = *src++; |
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if(filled >= width) { |
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filled = 0; |
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dst -= stride; |
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height--; |
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} |
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} |
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size -= code + 1; |
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} else if(code >= 0x80) { /* skip code: 0x80..0xBF */ |
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int skip; |
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code &= 0x3F; |
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/* codes 0x80 and 0x81 are actually escape codes, |
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skip value minus constant is in the next byte */ |
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if(!code) |
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skip = (*src++) + 64; |
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else if(code == 1) |
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skip = (*src++) + 320; |
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else |
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skip = code; |
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filled += skip; |
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while( filled >= width) { |
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filled -= width; |
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dst -= stride; |
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height--; |
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if(height < 0) |
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break; |
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} |
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} else { |
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/* zero code treated as one-pixel skip */ |
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if(code) |
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dst[filled++] = ctable[code & 0x7F]; |
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else |
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filled++; |
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if(filled >= width) { |
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filled = 0; |
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dst -= stride; |
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height--; |
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} |
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} |
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} |
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} |
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static int decode_frame(AVCodecContext *avctx, |
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void *data, int *data_size, |
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AVPacket *avpkt) |
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{ |
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const uint8_t *buf = avpkt->data; |
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int buf_size = avpkt->size; |
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QpegContext * const a = avctx->priv_data; |
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AVFrame * const p= (AVFrame*)&a->pic; |
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uint8_t* outdata; |
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int delta; |
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if(p->data[0]) |
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avctx->release_buffer(avctx, p); |
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p->reference= 0; |
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if(avctx->get_buffer(avctx, p) < 0){ |
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av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
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return -1; |
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} |
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outdata = a->pic.data[0]; |
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if(buf[0x85] == 0x10) { |
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qpeg_decode_intra(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height); |
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} else { |
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delta = buf[0x85]; |
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qpeg_decode_inter(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height, delta, buf + 4, a->refdata); |
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} |
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/* make the palette available on the way out */ |
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memcpy(a->pic.data[1], a->avctx->palctrl->palette, AVPALETTE_SIZE); |
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if (a->avctx->palctrl->palette_changed) { |
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a->pic.palette_has_changed = 1; |
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a->avctx->palctrl->palette_changed = 0; |
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} |
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*data_size = sizeof(AVFrame); |
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*(AVFrame*)data = a->pic; |
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return buf_size; |
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} |
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static av_cold int decode_init(AVCodecContext *avctx){ |
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QpegContext * const a = avctx->priv_data; |
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if (!avctx->palctrl) { |
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av_log(avctx, AV_LOG_FATAL, "Missing required palette via palctrl\n"); |
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return -1; |
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} |
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a->avctx = avctx; |
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avctx->pix_fmt= PIX_FMT_PAL8; |
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a->refdata = av_malloc(avctx->width * avctx->height); |
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return 0; |
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} |
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static av_cold int decode_end(AVCodecContext *avctx){ |
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QpegContext * const a = avctx->priv_data; |
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AVFrame * const p= (AVFrame*)&a->pic; |
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if(p->data[0]) |
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avctx->release_buffer(avctx, p); |
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av_free(a->refdata); |
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return 0; |
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} |
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AVCodec ff_qpeg_decoder = { |
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"qpeg", |
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AVMEDIA_TYPE_VIDEO, |
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CODEC_ID_QPEG, |
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sizeof(QpegContext), |
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decode_init, |
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NULL, |
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decode_end, |
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decode_frame, |
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CODEC_CAP_DR1, |
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.long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"), |
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};
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