yading@10: /*
yading@10:  * Microsoft RLE decoder
yading@10:  * Copyright (C) 2008 Konstantin Shishkov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * MS RLE decoder based on decoder by Mike Melanson and my own for TSCC
yading@10:  * For more information about the MS RLE format, visit:
yading@10:  *   http://www.multimedia.cx/msrle.txt
yading@10:  */
yading@10: 
yading@10: #include "libavutil/intreadwrite.h"
yading@10: #include "avcodec.h"
yading@10: #include "msrledec.h"
yading@10: 
yading@10: static int msrle_decode_pal4(AVCodecContext *avctx, AVPicture *pic,
yading@10:                              GetByteContext *gb)
yading@10: {
yading@10:     unsigned char rle_code;
yading@10:     unsigned char extra_byte, odd_pixel;
yading@10:     unsigned char stream_byte;
yading@10:     unsigned int pixel_ptr = 0;
yading@10:     int row_dec = pic->linesize[0];
yading@10:     int row_ptr = (avctx->height - 1) * row_dec;
yading@10:     int frame_size = row_dec * avctx->height;
yading@10:     int i;
yading@10: 
yading@10:     while (row_ptr >= 0) {
yading@10:         if (bytestream2_get_bytes_left(gb) <= 0) {
yading@10:             av_log(avctx, AV_LOG_ERROR,
yading@10:                    "MS RLE: bytestream overrun, %d rows left\n",
yading@10:                    row_ptr);
yading@10:             return AVERROR_INVALIDDATA;
yading@10:         }
yading@10:         rle_code = stream_byte = bytestream2_get_byteu(gb);
yading@10:         if (rle_code == 0) {
yading@10:             /* fetch the next byte to see how to handle escape code */
yading@10:             stream_byte = bytestream2_get_byte(gb);
yading@10:             if (stream_byte == 0) {
yading@10:                 /* line is done, goto the next one */
yading@10:                 row_ptr -= row_dec;
yading@10:                 pixel_ptr = 0;
yading@10:             } else if (stream_byte == 1) {
yading@10:                 /* decode is done */
yading@10:                 return 0;
yading@10:             } else if (stream_byte == 2) {
yading@10:                 /* reposition frame decode coordinates */
yading@10:                 stream_byte = bytestream2_get_byte(gb);
yading@10:                 pixel_ptr += stream_byte;
yading@10:                 stream_byte = bytestream2_get_byte(gb);
yading@10:                 row_ptr -= stream_byte * row_dec;
yading@10:             } else {
yading@10:                 // copy pixels from encoded stream
yading@10:                 odd_pixel =  stream_byte & 1;
yading@10:                 rle_code = (stream_byte + 1) / 2;
yading@10:                 extra_byte = rle_code & 0x01;
yading@10:                 if (row_ptr + pixel_ptr + stream_byte > frame_size ||
yading@10:                     bytestream2_get_bytes_left(gb) < rle_code) {
yading@10:                     av_log(avctx, AV_LOG_ERROR,
yading@10:                            "MS RLE: frame/stream ptr just went out of bounds (copy)\n");
yading@10:                     return AVERROR_INVALIDDATA;
yading@10:                 }
yading@10: 
yading@10:                 for (i = 0; i < rle_code; i++) {
yading@10:                     if (pixel_ptr >= avctx->width)
yading@10:                         break;
yading@10:                     stream_byte = bytestream2_get_byteu(gb);
yading@10:                     pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
yading@10:                     pixel_ptr++;
yading@10:                     if (i + 1 == rle_code && odd_pixel)
yading@10:                         break;
yading@10:                     if (pixel_ptr >= avctx->width)
yading@10:                         break;
yading@10:                     pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
yading@10:                     pixel_ptr++;
yading@10:                 }
yading@10: 
yading@10:                 // if the RLE code is odd, skip a byte in the stream
yading@10:                 if (extra_byte)
yading@10:                     bytestream2_skip(gb, 1);
yading@10:             }
yading@10:         } else {
yading@10:             // decode a run of data
yading@10:             if (row_ptr + pixel_ptr + stream_byte > frame_size) {
yading@10:                 av_log(avctx, AV_LOG_ERROR,
yading@10:                        "MS RLE: frame ptr just went out of bounds (run)\n");
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             }
yading@10:             stream_byte = bytestream2_get_byte(gb);
yading@10:             for (i = 0; i < rle_code; i++) {
yading@10:                 if (pixel_ptr >= avctx->width)
yading@10:                     break;
yading@10:                 if ((i & 1) == 0)
yading@10:                     pic->data[0][row_ptr + pixel_ptr] = stream_byte >> 4;
yading@10:                 else
yading@10:                     pic->data[0][row_ptr + pixel_ptr] = stream_byte & 0x0F;
yading@10:                 pixel_ptr++;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     /* one last sanity check on the way out */
yading@10:     if (bytestream2_get_bytes_left(gb)) {
yading@10:         av_log(avctx, AV_LOG_ERROR,
yading@10:                "MS RLE: ended frame decode with %d bytes left over\n",
yading@10:                bytestream2_get_bytes_left(gb));
yading@10:         return AVERROR_INVALIDDATA;
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: 
yading@10: static int msrle_decode_8_16_24_32(AVCodecContext *avctx, AVPicture *pic,
yading@10:                                    int depth, GetByteContext *gb)
yading@10: {
yading@10:     uint8_t *output, *output_end;
yading@10:     int p1, p2, line=avctx->height - 1, pos=0, i;
yading@10:     uint16_t pix16;
yading@10:     uint32_t pix32;
yading@10:     unsigned int width= FFABS(pic->linesize[0]) / (depth >> 3);
yading@10: 
yading@10:     output     = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
yading@10:     output_end = output + FFABS(pic->linesize[0]);
yading@10: 
yading@10:     while (bytestream2_get_bytes_left(gb) > 0) {
yading@10:         p1 = bytestream2_get_byteu(gb);
yading@10:         if(p1 == 0) { //Escape code
yading@10:             p2 = bytestream2_get_byte(gb);
yading@10:             if(p2 == 0) { //End-of-line
yading@10:                 if (--line < 0) {
yading@10:                     if (bytestream2_get_be16(gb) == 1) { // end-of-picture
yading@10:                         return 0;
yading@10:                     } else {
yading@10:                         av_log(avctx, AV_LOG_ERROR,
yading@10:                                "Next line is beyond picture bounds (%d bytes left)\n",
yading@10:                                bytestream2_get_bytes_left(gb));
yading@10:                         return AVERROR_INVALIDDATA;
yading@10:                     }
yading@10:                 }
yading@10:                 output = pic->data[0] + line * pic->linesize[0];
yading@10:                 output_end = output + FFABS(pic->linesize[0]);
yading@10:                 pos = 0;
yading@10:                 continue;
yading@10:             } else if(p2 == 1) { //End-of-picture
yading@10:                 return 0;
yading@10:             } else if(p2 == 2) { //Skip
yading@10:                 p1 = bytestream2_get_byte(gb);
yading@10:                 p2 = bytestream2_get_byte(gb);
yading@10:                 line -= p2;
yading@10:                 pos += p1;
yading@10:                 if (line < 0 || pos >= width){
yading@10:                     av_log(avctx, AV_LOG_ERROR, "Skip beyond picture bounds\n");
yading@10:                     return -1;
yading@10:                 }
yading@10:                 output = pic->data[0] + line * pic->linesize[0] + pos * (depth >> 3);
yading@10:                 output_end = pic->data[0] + line * pic->linesize[0] + FFABS(pic->linesize[0]);
yading@10:                 continue;
yading@10:             }
yading@10:             // Copy data
yading@10:             if (output + p2 * (depth >> 3) > output_end) {
yading@10:                 bytestream2_skip(gb, 2 * (depth >> 3));
yading@10:                 continue;
yading@10:             } else if (bytestream2_get_bytes_left(gb) < p2 * (depth >> 3)) {
yading@10:                 av_log(avctx, AV_LOG_ERROR, "bytestream overrun\n");
yading@10:                 return AVERROR_INVALIDDATA;
yading@10:             }
yading@10: 
yading@10:             if ((depth == 8) || (depth == 24)) {
yading@10:                 for(i = 0; i < p2 * (depth >> 3); i++) {
yading@10:                     *output++ = bytestream2_get_byteu(gb);
yading@10:                 }
yading@10:                 // RLE8 copy is actually padded - and runs are not!
yading@10:                 if(depth == 8 && (p2 & 1)) {
yading@10:                     bytestream2_skip(gb, 1);
yading@10:                 }
yading@10:             } else if (depth == 16) {
yading@10:                 for(i = 0; i < p2; i++) {
yading@10:                     *(uint16_t*)output = bytestream2_get_le16u(gb);
yading@10:                     output += 2;
yading@10:                 }
yading@10:             } else if (depth == 32) {
yading@10:                 for(i = 0; i < p2; i++) {
yading@10:                     *(uint32_t*)output = bytestream2_get_le32u(gb);
yading@10:                     output += 4;
yading@10:                 }
yading@10:             }
yading@10:             pos += p2;
yading@10:         } else { //run of pixels
yading@10:             uint8_t pix[3]; //original pixel
yading@10:             if (output + p1 * (depth >> 3) > output_end)
yading@10:                 continue;
yading@10: 
yading@10:             switch(depth){
yading@10:             case  8:
yading@10:                 pix[0] = bytestream2_get_byte(gb);
yading@10:                 for(i = 0; i < p1; i++)
yading@10:                         *output++ = pix[0];
yading@10:                 break;
yading@10:             case 16:
yading@10:                 pix16  = bytestream2_get_le16(gb);
yading@10:                 for(i = 0; i < p1; i++) {
yading@10:                         *(uint16_t*)output = pix16;
yading@10:                         output += 2;
yading@10:                 }
yading@10:                 break;
yading@10:             case 24:
yading@10:                 pix[0] = bytestream2_get_byte(gb);
yading@10:                 pix[1] = bytestream2_get_byte(gb);
yading@10:                 pix[2] = bytestream2_get_byte(gb);
yading@10:                 for(i = 0; i < p1; i++) {
yading@10:                         *output++ = pix[0];
yading@10:                         *output++ = pix[1];
yading@10:                         *output++ = pix[2];
yading@10:                 }
yading@10:                 break;
yading@10:             case 32:
yading@10:                 pix32  = bytestream2_get_le32(gb);
yading@10:                 for(i = 0; i < p1; i++) {
yading@10:                         *(uint32_t*)output = pix32;
yading@10:                         output += 4;
yading@10:                 }
yading@10:                 break;
yading@10:             }
yading@10:             pos += p1;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     av_log(avctx, AV_LOG_WARNING, "MS RLE warning: no end-of-picture code\n");
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: 
yading@10: int ff_msrle_decode(AVCodecContext *avctx, AVPicture *pic,
yading@10:                     int depth, GetByteContext *gb)
yading@10: {
yading@10:     switch(depth){
yading@10:     case  4:
yading@10:         return msrle_decode_pal4(avctx, pic, gb);
yading@10:     case  8:
yading@10:     case 16:
yading@10:     case 24:
yading@10:     case 32:
yading@10:         return msrle_decode_8_16_24_32(avctx, pic, depth, gb);
yading@10:     default:
yading@10:         av_log(avctx, AV_LOG_ERROR, "Unknown depth %d\n", depth);
yading@10:         return -1;
yading@10:     }
yading@10: }