1/* 2 * Bethesda VID video decoder 3 * Copyright (C) 2007 Nicholas Tung 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * @brief Bethesda Softworks VID Video Decoder 25 * @author Nicholas Tung [ntung (at. ntung com] (2007-03) 26 * @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID 27 * @sa http://www.svatopluk.com/andux/docs/dfvid.html 28 */ 29 30#include "libavutil/common.h" 31#include "dsputil.h" 32#include "bethsoftvideo.h" 33#include "bytestream.h" 34 35typedef struct BethsoftvidContext { 36 AVFrame frame; 37} BethsoftvidContext; 38 39static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx) 40{ 41 BethsoftvidContext *vid = avctx->priv_data; 42 vid->frame.reference = 1; 43 vid->frame.buffer_hints = FF_BUFFER_HINTS_VALID | 44 FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE; 45 avctx->pix_fmt = PIX_FMT_PAL8; 46 return 0; 47} 48 49static void set_palette(AVFrame * frame, const uint8_t * palette_buffer) 50{ 51 uint32_t * palette = (uint32_t *)frame->data[1]; 52 int a; 53 for(a = 0; a < 256; a++){ 54 palette[a] = AV_RB24(&palette_buffer[a * 3]) * 4; 55 } 56 frame->palette_has_changed = 1; 57} 58 59static int bethsoftvid_decode_frame(AVCodecContext *avctx, 60 void *data, int *data_size, 61 AVPacket *avpkt) 62{ 63 const uint8_t *buf = avpkt->data; 64 int buf_size = avpkt->size; 65 BethsoftvidContext * vid = avctx->priv_data; 66 char block_type; 67 uint8_t * dst; 68 uint8_t * frame_end; 69 int remaining = avctx->width; // number of bytes remaining on a line 70 const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width; 71 int code; 72 int yoffset; 73 74 if (avctx->reget_buffer(avctx, &vid->frame)) { 75 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n"); 76 return -1; 77 } 78 dst = vid->frame.data[0]; 79 frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height; 80 81 switch(block_type = *buf++){ 82 case PALETTE_BLOCK: 83 set_palette(&vid->frame, buf); 84 return 0; 85 case VIDEO_YOFF_P_FRAME: 86 yoffset = bytestream_get_le16(&buf); 87 if(yoffset >= avctx->height) 88 return -1; 89 dst += vid->frame.linesize[0] * yoffset; 90 } 91 92 // main code 93 while((code = *buf++)){ 94 int length = code & 0x7f; 95 96 // copy any bytes starting at the current position, and ending at the frame width 97 while(length > remaining){ 98 if(code < 0x80) 99 bytestream_get_buffer(&buf, dst, remaining); 100 else if(block_type == VIDEO_I_FRAME) 101 memset(dst, buf[0], remaining); 102 length -= remaining; // decrement the number of bytes to be copied 103 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame 104 remaining = avctx->width; 105 if(dst == frame_end) 106 goto end; 107 } 108 109 // copy any remaining bytes after / if line overflows 110 if(code < 0x80) 111 bytestream_get_buffer(&buf, dst, length); 112 else if(block_type == VIDEO_I_FRAME) 113 memset(dst, *buf++, length); 114 remaining -= length; 115 dst += length; 116 } 117 end: 118 119 *data_size = sizeof(AVFrame); 120 *(AVFrame*)data = vid->frame; 121 122 return buf_size; 123} 124 125static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx) 126{ 127 BethsoftvidContext * vid = avctx->priv_data; 128 if(vid->frame.data[0]) 129 avctx->release_buffer(avctx, &vid->frame); 130 return 0; 131} 132 133AVCodec bethsoftvid_decoder = { 134 .name = "bethsoftvid", 135 .type = AVMEDIA_TYPE_VIDEO, 136 .id = CODEC_ID_BETHSOFTVID, 137 .priv_data_size = sizeof(BethsoftvidContext), 138 .init = bethsoftvid_decode_init, 139 .close = bethsoftvid_decode_end, 140 .decode = bethsoftvid_decode_frame, 141 .capabilities = CODEC_CAP_DR1, 142 .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"), 143}; 144