mirror of https://github.com/FFmpeg/FFmpeg.git
Konstantin Shishkov Originally committed as revision 4099 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
Mike Melanson
20 years ago
parent
16543599cc
commit
589f82202c
7 changed files with 182 additions and 2 deletions
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/*
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* Autodesc RLE Decoder |
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* Copyright (C) 2005 the ffmpeg project |
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* |
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* This library 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 of the License, or (at your option) any later version. |
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* |
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* This library 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 this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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/**
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* @file aasc.c |
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* Autodesc RLE Video Decoder by Konstantin Shishkov |
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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 "common.h" |
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#include "avcodec.h" |
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#include "dsputil.h" |
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typedef struct AascContext { |
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AVCodecContext *avctx; |
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AVFrame frame; |
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} AascContext; |
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#define FETCH_NEXT_STREAM_BYTE() \ |
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if (stream_ptr >= buf_size) \
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{ \
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av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (fetch)\n"); \
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break; \
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} \
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stream_byte = buf[stream_ptr++]; |
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static int aasc_decode_init(AVCodecContext *avctx) |
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{ |
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AascContext *s = (AascContext *)avctx->priv_data; |
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s->avctx = avctx; |
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avctx->pix_fmt = PIX_FMT_BGR24; |
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avctx->has_b_frames = 0; |
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s->frame.data[0] = NULL; |
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return 0; |
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} |
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static int aasc_decode_frame(AVCodecContext *avctx, |
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void *data, int *data_size, |
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uint8_t *buf, int buf_size) |
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{ |
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AascContext *s = (AascContext *)avctx->priv_data; |
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int stream_ptr = 4; |
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unsigned char rle_code; |
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unsigned char stream_byte; |
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int pixel_ptr = 0; |
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int row_dec, row_ptr; |
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int frame_size; |
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int i; |
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s->frame.reference = 1; |
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s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; |
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if (avctx->reget_buffer(avctx, &s->frame)) { |
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av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); |
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return -1; |
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} |
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row_dec = s->frame.linesize[0]; |
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row_ptr = (s->avctx->height - 1) * row_dec; |
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frame_size = row_dec * s->avctx->height; |
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while (row_ptr >= 0) { |
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FETCH_NEXT_STREAM_BYTE(); |
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rle_code = stream_byte; |
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if (rle_code == 0) { |
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/* fetch the next byte to see how to handle escape code */ |
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FETCH_NEXT_STREAM_BYTE(); |
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if (stream_byte == 0) { |
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/* line is done, goto the next one */ |
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row_ptr -= row_dec; |
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pixel_ptr = 0; |
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} else if (stream_byte == 1) { |
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/* decode is done */ |
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break; |
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} else if (stream_byte == 2) { |
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/* reposition frame decode coordinates */ |
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FETCH_NEXT_STREAM_BYTE(); |
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pixel_ptr += stream_byte; |
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FETCH_NEXT_STREAM_BYTE(); |
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row_ptr -= stream_byte * row_dec; |
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} else { |
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/* copy pixels from encoded stream */ |
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if ((pixel_ptr + stream_byte > avctx->width * 3) || |
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(row_ptr < 0)) { |
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av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (copy1)\n"); |
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break; |
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} |
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rle_code = stream_byte; |
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if (stream_ptr + rle_code > buf_size) { |
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av_log(s->avctx, AV_LOG_ERROR, " AASC: stream ptr just went out of bounds (copy2)\n"); |
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break; |
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} |
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for (i = 0; i < rle_code; i++) { |
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FETCH_NEXT_STREAM_BYTE(); |
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s->frame.data[0][row_ptr + pixel_ptr] = stream_byte; |
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pixel_ptr++; |
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} |
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if (rle_code & 1) |
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stream_ptr++; |
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} |
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} else { |
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/* decode a run of data */ |
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if ((pixel_ptr + rle_code > avctx->width * 3) || |
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(row_ptr < 0)) { |
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av_log(s->avctx, AV_LOG_ERROR, " AASC: frame ptr just went out of bounds (run1)\n"); |
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break; |
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} |
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FETCH_NEXT_STREAM_BYTE(); |
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while(rle_code--) { |
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s->frame.data[0][row_ptr + pixel_ptr] = stream_byte; |
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pixel_ptr++; |
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} |
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} |
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} |
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/* one last sanity check on the way out */ |
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if (stream_ptr < buf_size) |
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av_log(s->avctx, AV_LOG_ERROR, " AASC: ended frame decode with bytes left over (%d < %d)\n", |
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stream_ptr, buf_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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static int aasc_decode_end(AVCodecContext *avctx) |
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{ |
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AascContext *s = (AascContext *)avctx->priv_data; |
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/* release the last frame */ |
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if (s->frame.data[0]) |
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avctx->release_buffer(avctx, &s->frame); |
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return 0; |
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} |
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AVCodec aasc_decoder = { |
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"aasc", |
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CODEC_TYPE_VIDEO, |
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CODEC_ID_AASC, |
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sizeof(AascContext), |
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aasc_decode_init, |
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NULL, |
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aasc_decode_end, |
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aasc_decode_frame, |
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CODEC_CAP_DR1, |
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}; |
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