mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 12543 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Sascha Sommer
17 years ago
parent
433aeb6240
commit
975cdc8fc1
4 changed files with 244 additions and 1 deletions
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/*
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* RL2 Video Decoder |
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* Copyright (C) 2008 Sascha Sommer (saschasommer@freenet.de) |
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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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* RL2 Video Decoder |
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* @file rl2.c |
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* @author Sascha Sommer (saschasommer@freenet.de) |
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* For more information about the RL2 format, visit: |
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* http://wiki.multimedia.cx/index.php?title=RL2
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*/ |
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#include <stdio.h> |
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#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include "avcodec.h" |
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#define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr count, palette
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typedef struct Rl2Context { |
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AVCodecContext *avctx; |
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AVFrame frame; |
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unsigned short video_base; ///< initial drawing offset
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unsigned int clr_count; ///< number of used colors (currently unused)
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unsigned char* back_frame; ///< background frame
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unsigned int palette[AVPALETTE_COUNT]; |
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} Rl2Context; |
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/**
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* Run Length Decode a single 320x200 frame |
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* @param s rl2 context |
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* @param buf input buffer |
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* @param size input buffer size |
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* @param out ouput buffer |
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* @param stride stride of the output buffer |
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* @param video_base offset of the rle data inside the frame |
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*/ |
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static void rl2_rle_decode(Rl2Context *s,const unsigned char* in,int size, |
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unsigned char* out,int stride,int video_base){ |
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int base_x = video_base % s->avctx->width; |
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int base_y = video_base / s->avctx->width; |
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int stride_adj = stride - s->avctx->width; |
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int i; |
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const unsigned char* back_frame = s->back_frame; |
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const unsigned char* in_end = in + size; |
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const unsigned char* out_end = out + stride * s->avctx->height; |
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unsigned char* line_end = out + s->avctx->width; |
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/** copy start of the background frame */ |
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for(i=0;i<=base_y;i++){ |
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if(s->back_frame) |
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memcpy(out,back_frame,s->avctx->width); |
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out += stride; |
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back_frame += s->avctx->width; |
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} |
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back_frame += base_x - s->avctx->width; |
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line_end = out - stride_adj; |
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out += base_x - stride; |
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/** decode the variable part of the frame */ |
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while(in < in_end){ |
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unsigned char val = *in++; |
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int len = 1; |
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if(val >= 0x80){ |
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if(in >= in_end) |
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break; |
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len = *in++; |
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if(!len) |
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break; |
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} |
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if(len >= out_end - out) |
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break; |
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if(s->back_frame) |
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val |= 0x80; |
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else |
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val &= ~0x80; |
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while(len--){ |
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*out++ = (val == 0x80)? *back_frame:val; |
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back_frame++; |
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if(out == line_end){ |
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out += stride_adj; |
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line_end += stride; |
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if(len >= out_end - out) |
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break; |
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} |
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} |
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} |
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/** copy the rest from the background frame */ |
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if(s->back_frame){ |
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while(out < out_end){ |
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memcpy(out, back_frame, line_end - out); |
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back_frame += line_end - out; |
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out = line_end + stride_adj; |
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line_end += stride; |
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} |
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} |
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} |
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/**
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* Initialize the decoder |
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* @param avctx decoder context |
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* @return 0 success, -1 on error |
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*/ |
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static av_cold int rl2_decode_init(AVCodecContext *avctx) |
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{ |
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Rl2Context *s = avctx->priv_data; |
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int back_size; |
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int i; |
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s->avctx = avctx; |
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avctx->pix_fmt = PIX_FMT_PAL8; |
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/** parse extra data */ |
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if(!avctx->extradata || avctx->extradata_size < EXTRADATA1_SIZE){ |
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av_log(avctx, AV_LOG_ERROR, "invalid extradata size\n"); |
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return -1; |
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} |
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/** get frame_offset */ |
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s->video_base = AV_RL16(&avctx->extradata[0]); |
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s->clr_count = AV_RL32(&avctx->extradata[2]); |
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if(s->video_base >= avctx->width * avctx->height){ |
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av_log(avctx, AV_LOG_ERROR, "invalid video_base\n"); |
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return -1; |
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} |
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/** initialize palette */ |
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for(i=0;i<AVPALETTE_COUNT;i++) |
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s->palette[i] = AV_RB24(&avctx->extradata[6 + i * 3]); |
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/** decode background frame if present */ |
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back_size = avctx->extradata_size - EXTRADATA1_SIZE; |
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if(back_size > 0){ |
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unsigned char* back_frame = av_mallocz(avctx->width*avctx->height); |
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if(!back_frame) |
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return -1; |
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rl2_rle_decode(s,avctx->extradata + EXTRADATA1_SIZE,back_size, |
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back_frame,avctx->width,0); |
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s->back_frame = back_frame; |
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} |
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return 0; |
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} |
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/**
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* Decode a single frame |
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* @param avctx decoder context |
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* @param data decoded frame |
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* @param data_size size of the decoded frame |
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* @param buf input buffer |
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* @param buf_size input buffer size |
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* @return 0 success, -1 on error |
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*/ |
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static int rl2_decode_frame(AVCodecContext *avctx, |
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void *data, int *data_size, |
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const uint8_t *buf, int buf_size) |
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{ |
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Rl2Context *s = avctx->priv_data; |
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if(s->frame.data[0]) |
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avctx->release_buffer(avctx, &s->frame); |
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/** get buffer */ |
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s->frame.reference= 0; |
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if(avctx->get_buffer(avctx, &s->frame)) { |
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av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n"); |
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return -1; |
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} |
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/** run length decode */ |
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rl2_rle_decode(s,buf,buf_size,s->frame.data[0],s->frame.linesize[0],s->video_base); |
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/** make the palette available on the way out */ |
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memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE); |
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*data_size = sizeof(AVFrame); |
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*(AVFrame*)data = s->frame; |
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/** report that the buffer was completely consumed */ |
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return buf_size; |
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} |
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/**
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* Uninit decoder |
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* @param avctx decoder context |
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* @return 0 success, -1 on error |
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*/ |
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static av_cold int rl2_decode_end(AVCodecContext *avctx) |
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{ |
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Rl2Context *s = avctx->priv_data; |
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if(s->frame.data[0]) |
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avctx->release_buffer(avctx, &s->frame); |
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av_free(s->back_frame); |
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return 0; |
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} |
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AVCodec rl2_decoder = { |
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"rl2", |
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CODEC_TYPE_VIDEO, |
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CODEC_ID_RL2, |
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sizeof(Rl2Context), |
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rl2_decode_init, |
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NULL, |
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rl2_decode_end, |
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rl2_decode_frame, |
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CODEC_CAP_DR1, |
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}; |
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