| /* |
| * Microsoft 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 |
| * 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" |
| #include "msrledec.h" |
| |
| static int msrle_decode_pal4(AVCodecContext *avctx, AVFrame *pic, |
| GetByteContext *gb) |
| { |
| unsigned char rle_code; |
| unsigned char extra_byte, odd_pixel; |
| unsigned char stream_byte; |
| int pixel_ptr = 0; |
| int line = avctx->height - 1; |
| int i; |
| |
| while (line >= 0 && pixel_ptr <= avctx->width) { |
| if (bytestream2_get_bytes_left(gb) <= 0) { |
| av_log(avctx, AV_LOG_ERROR, |
| "MS RLE: bytestream overrun, %dx%d left\n", |
| avctx->width - pixel_ptr, line); |
| return AVERROR_INVALIDDATA; |
| } |
| rle_code = stream_byte = bytestream2_get_byteu(gb); |
| if (rle_code == 0) { |
| /* fetch the next byte to see how to handle escape code */ |
| stream_byte = bytestream2_get_byte(gb); |
| if (stream_byte == 0) { |
| /* line is done, goto the next one */ |
| line--; |
| pixel_ptr = 0; |
| } else if (stream_byte == 1) { |
| /* decode is done */ |
| return 0; |
| } else if (stream_byte == 2) { |
| /* reposition frame decode coordinates */ |
| stream_byte = bytestream2_get_byte(gb); |
| pixel_ptr += stream_byte; |
| stream_byte = bytestream2_get_byte(gb); |
| line -= stream_byte; |
| } else { |
| // copy pixels from encoded stream |
| odd_pixel = stream_byte & 1; |
| rle_code = (stream_byte + 1) / 2; |
| extra_byte = rle_code & 0x01; |
| if (pixel_ptr + 2*rle_code - odd_pixel > avctx->width || |
| bytestream2_get_bytes_left(gb) < rle_code) { |
| av_log(avctx, AV_LOG_ERROR, |
| "MS RLE: frame/stream ptr just went out of bounds (copy)\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| for (i = 0; i < rle_code; i++) { |
| if (pixel_ptr >= avctx->width) |
| break; |
| stream_byte = bytestream2_get_byteu(gb); |
| pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4; |
| pixel_ptr++; |
| if (i + 1 == rle_code && odd_pixel) |
| break; |
| if (pixel_ptr >= avctx->width) |
| break; |
| pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F; |
| pixel_ptr++; |
| } |
| |
| // if the RLE code is odd, skip a byte in the stream |
| if (extra_byte) |
| bytestream2_skip(gb, 1); |
| } |
| } else { |
| // decode a run of data |
| if (pixel_ptr + rle_code > avctx->width + 1) { |
| av_log(avctx, AV_LOG_ERROR, |
| "MS RLE: frame ptr just went out of bounds (run) %d %d %d\n", pixel_ptr, rle_code, avctx->width); |
| return AVERROR_INVALIDDATA; |
| } |
| stream_byte = bytestream2_get_byte(gb); |
| for (i = 0; i < rle_code; i++) { |
| if (pixel_ptr >= avctx->width) |
| break; |
| if ((i & 1) == 0) |
| pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte >> 4; |
| else |
| pic->data[0][line * pic->linesize[0] + pixel_ptr] = stream_byte & 0x0F; |
| pixel_ptr++; |
| } |
| } |
| } |
| |
| /* one last sanity check on the way out */ |
| if (bytestream2_get_bytes_left(gb)) { |
| av_log(avctx, AV_LOG_ERROR, |
| "MS RLE: ended frame decode with %d bytes left over\n", |
| bytestream2_get_bytes_left(gb)); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVFrame *pic, |
| int depth, GetByteContext *gb) |
| { |
| uint8_t *output, *output_end; |
| int p1, p2, line=avctx->height - 1, pos=0, i; |
| uint16_t pix16; |
| uint32_t pix32; |
| unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3); |
| |
| output = pic->data[0] + (avctx->height - 1) * pic->linesize[0]; |
| output_end = output + FFABS(pic->linesize[0]); |
| |
| while (bytestream2_get_bytes_left(gb) > 0) { |
| p1 = bytestream2_get_byteu(gb); |
| if(p1 == 0) { //Escape code |
| p2 = bytestream2_get_byte(gb); |
| if(p2 == 0) { //End-of-line |
| if (--line < 0) { |
| if (bytestream2_get_be16(gb) == 1) { // end-of-picture |
| return 0; |
| } else { |
| av_log(avctx, AV_LOG_ERROR, |
| "Next line is beyond picture bounds (%d bytes left)\n", |
| bytestream2_get_bytes_left(gb)); |
| return AVERROR_INVALIDDATA; |
| } |
| } |
| output = pic->data[0] + line * pic->linesize[0]; |
| output_end = output + FFABS(pic->linesize[0]); |
| pos = 0; |
| continue; |
| } else if(p2 == 1) { //End-of-picture |
| return 0; |
| } else if(p2 == 2) { //Skip |
| p1 = bytestream2_get_byte(gb); |
| p2 = bytestream2_get_byte(gb); |
| line -= p2; |
| pos += p1; |
| if (line < 0 || pos >= width){ |
| av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n"); |
| return -1; |
| } |
| output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3); |
| output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]); |
| continue; |
| } |
| // Copy data |
| if (output + p2 * (depth >> 3) > output_end) { |
| bytestream2_skip(gb, 2 * (depth >> 3)); |
| continue; |
| } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) { |
| av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if ((depth == 8) || (depth == 24)) { |
| bytestream2_get_bufferu(gb, output, p2 * (depth >> 3)); |
| output += p2 * (depth >> 3); |
| |
| // RLE8 copy is actually padded - and runs are not! |
| if(depth == 8 && (p2 & 1)) { |
| bytestream2_skip(gb, 1); |
| } |
| } else if (depth == 16) { |
| for(i = 0; i < p2; i++) { |
| *(uint16_t*)output = bytestream2_get_le16u(gb); |
| output += 2; |
| } |
| } else if (depth == 32) { |
| for(i = 0; i < p2; i++) { |
| *(uint32_t*)output = bytestream2_get_le32u(gb); |
| output += 4; |
| } |
| } |
| pos += p2; |
| } else { //run of pixels |
| uint8_t pix[3]; //original pixel |
| if (output + p1 * (depth >> 3) > output_end) |
| continue; |
| |
| switch(depth){ |
| case 8: |
| pix[0] = bytestream2_get_byte(gb); |
| memset(output, pix[0], p1); |
| output += p1; |
| break; |
| case 16: |
| pix16 = bytestream2_get_le16(gb); |
| for(i = 0; i < p1; i++) { |
| *(uint16_t*)output = pix16; |
| output += 2; |
| } |
| break; |
| case 24: |
| pix[0] = bytestream2_get_byte(gb); |
| pix[1] = bytestream2_get_byte(gb); |
| pix[2] = bytestream2_get_byte(gb); |
| for(i = 0; i < p1; i++) { |
| *output++ = pix[0]; |
| *output++ = pix[1]; |
| *output++ = pix[2]; |
| } |
| break; |
| case 32: |
| pix32 = bytestream2_get_le32(gb); |
| for(i = 0; i < p1; i++) { |
| *(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, AVFrame *pic, |
| int depth, GetByteContext *gb) |
| { |
| switch(depth){ |
| case 4: |
| return msrle_decode_pal4(avctx, pic, gb); |
| case 8: |
| case 16: |
| case 24: |
| case 32: |
| return msrle_decode_8_16_24_32(avctx, pic, depth, gb); |
| default: |
| av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth); |
| return -1; |
| } |
| } |
