| /* |
| * Micrsoft RLE Decoder |
| * Copyright (C) 2008 Konstantin Shishkov |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file libavcodec/msrledec.c |
| * MS RLE Decoder based on decoder by Mike Melanson and my own for TSCC |
| * For more information about the MS RLE format, visit: |
| * http://www.multimedia.cx/msrle.txt |
| */ |
| |
| #include "libavutil/intreadwrite.h" |
| #include "avcodec.h" |
| |
| #define FETCH_NEXT_STREAM_BYTE() \ |
| if (stream_ptr >= data_size) \ |
| { \ |
| av_log(avctx, AV_LOG_ERROR, " MS RLE: stream ptr just went out of bounds (1)\n"); \ |
| return -1; \ |
| } \ |
| stream_byte = data[stream_ptr++]; |
| |
| static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic, |
| const uint8_t *data, int data_size) |
| { |
| int stream_ptr = 0; |
| unsigned char rle_code; |
| unsigned char extra_byte, odd_pixel; |
| unsigned char stream_byte; |
| int pixel_ptr = 0; |
| int row_dec = pic->linesize[0]; |
| int row_ptr = (avctx->height - 1) * row_dec; |
| int frame_size = row_dec * avctx->height; |
| int i; |
| |
| while (row_ptr >= 0) { |
| FETCH_NEXT_STREAM_BYTE(); |
| rle_code = stream_byte; |
| if (rle_code == 0) { |
| /* fetch the next byte to see how to handle escape code */ |
| FETCH_NEXT_STREAM_BYTE(); |
| if (stream_byte == 0) { |
| /* line is done, goto the next one */ |
| row_ptr -= row_dec; |
| pixel_ptr = 0; |
| } else if (stream_byte == 1) { |
| /* decode is done */ |
| return 0; |
| } else if (stream_byte == 2) { |
| /* reposition frame decode coordinates */ |
| FETCH_NEXT_STREAM_BYTE(); |
| pixel_ptr += stream_byte; |
| FETCH_NEXT_STREAM_BYTE(); |
| row_ptr -= stream_byte * row_dec; |
| } else { |
| // copy pixels from encoded stream |
| odd_pixel = stream_byte & 1; |
| rle_code = (stream_byte + 1) / 2; |
| extra_byte = rle_code & 0x01; |
| if ((row_ptr + pixel_ptr + stream_byte > frame_size) || |
| (row_ptr < 0)) { |
| av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n"); |
| return -1; |
| } |
| |
| for (i = 0; i < rle_code; i++) { |
| if (pixel_ptr >= avctx->width) |
| break; |
| FETCH_NEXT_STREAM_BYTE(); |
| pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4; |
| pixel_ptr++; |
| if (i + 1 == rle_code && odd_pixel) |
| break; |
| if (pixel_ptr >= avctx->width) |
| break; |
| pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F; |
| pixel_ptr++; |
| } |
| |
| // if the RLE code is odd, skip a byte in the stream |
| if (extra_byte) |
| stream_ptr++; |
| } |
| } else { |
| // decode a run of data |
| if ((row_ptr + pixel_ptr + stream_byte > frame_size) || |
| (row_ptr < 0)) { |
| av_log(avctx, AV_LOG_ERROR, " MS RLE: frame ptr just went out of bounds (1)\n"); |
| return -1; |
| } |
| FETCH_NEXT_STREAM_BYTE(); |
| for (i = 0; i < rle_code; i++) { |
| if (pixel_ptr >= avctx->width) |
| break; |
| if ((i & 1) == 0) |
| pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4; |
| else |
| pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F; |
| pixel_ptr++; |
| } |
| } |
| } |
| |
| /* one last sanity check on the way out */ |
| if (stream_ptr < data_size) { |
| av_log(avctx, AV_LOG_ERROR, " MS RLE: ended frame decode with bytes left over (%d < %d)\n", |
| stream_ptr, data_size); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic, int depth, |
| const uint8_t *data, int srcsize) |
| { |
| uint8_t *output, *output_end; |
| const uint8_t* src = data; |
| int p1, p2, line=avctx->height, pos=0, i; |
| uint16_t av_uninit(pix16); |
| uint32_t av_uninit(pix32); |
| |
| output = pic->data[0] + (avctx->height - 1) * pic->linesize[0]; |
| output_end = pic->data[0] + (avctx->height) * pic->linesize[0]; |
| while(src < data + srcsize) { |
| p1 = *src++; |
| if(p1 == 0) { //Escape code |
| p2 = *src++; |
| if(p2 == 0) { //End-of-line |
| output = pic->data[0] + (--line) * pic->linesize[0]; |
| if (line < 0){ |
| av_log(avctx, AV_LOG_ERROR, "Next line is beyond picture bounds\n"); |
| return -1; |
| } |
| pos = 0; |
| continue; |
| } else if(p2 == 1) { //End-of-picture |
| return 0; |
| } else if(p2 == 2) { //Skip |
| p1 = *src++; |
| p2 = *src++; |
| line -= p2; |
| if (line < 0){ |
| av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n"); |
| return -1; |
| } |
| pos += p1; |
| output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3); |
| continue; |
| } |
| // Copy data |
| if (output + p2 * (depth >> 3) > output_end) { |
| src += p2 * (depth >> 3); |
| continue; |
| } |
| if ((depth == 8) || (depth == 24)) { |
| for(i = 0; i < p2 * (depth >> 3); i++) { |
| *output++ = *src++; |
| } |
| // RLE8 copy is actually padded - and runs are not! |
| if(depth == 8 && (p2 & 1)) { |
| src++; |
| } |
| } else if (depth == 16) { |
| for(i = 0; i < p2; i++) { |
| pix16 = AV_RL16(src); |
| src += 2; |
| *(uint16_t*)output = pix16; |
| output += 2; |
| } |
| } else if (depth == 32) { |
| for(i = 0; i < p2; i++) { |
| pix32 = AV_RL32(src); |
| src += 4; |
| *(uint32_t*)output = pix32; |
| output += 4; |
| } |
| } |
| pos += p2; |
| } else { //Run of pixels |
| uint8_t pix[3]; //original pixel |
| switch(depth){ |
| case 8: pix[0] = *src++; |
| break; |
| case 16: pix16 = AV_RL16(src); |
| src += 2; |
| break; |
| case 24: pix[0] = *src++; |
| pix[1] = *src++; |
| pix[2] = *src++; |
| break; |
| case 32: pix32 = AV_RL32(src); |
| src += 4; |
| break; |
| } |
| if (output + p1 * (depth >> 3) > output_end) |
| continue; |
| for(i = 0; i < p1; i++) { |
| switch(depth){ |
| case 8: *output++ = pix[0]; |
| break; |
| case 16: *(uint16_t*)output = pix16; |
| output += 2; |
| break; |
| case 24: *output++ = pix[0]; |
| *output++ = pix[1]; |
| *output++ = pix[2]; |
| break; |
| case 32: *(uint32_t*)output = pix32; |
| output += 4; |
| break; |
| } |
| } |
| pos += p1; |
| } |
| } |
| |
| av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no End-of-picture code\n"); |
| return 0; |
| } |
| |
| |
| int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic, int depth, |
| const uint8_t* data, int data_size) |
| { |
| switch(depth){ |
| case 4: |
| return msrle_decode_pal4(avctx, pic, data, data_size); |
| case 8: |
| case 16: |
| case 24: |
| case 32: |
| return msrle_decode_8_16_24_32(avctx, pic, depth, data, data_size); |
| default: |
| av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth); |
| return -1; |
| } |
| } |
| |
