2 * Bethesda VID video decoder
3 * Copyright (C) 2007 Nicholas Tung
5 * This file is part of Libav.
7 * Libav 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.
12 * Libav 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.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * @brief Bethesda Softworks VID Video Decoder
25 * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
26 * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27 * @see http://www.svatopluk.com/andux/docs/dfvid.html
30 #include "libavutil/common.h"
32 #include "bethsoftvideo.h"
33 #include "bytestream.h"
35 typedef struct BethsoftvidContext {
40 static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
42 BethsoftvidContext *vid = avctx->priv_data;
43 vid->frame.reference = 1;
44 vid->frame.buffer_hints = FF_BUFFER_HINTS_VALID |
45 FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
46 avctx->pix_fmt = PIX_FMT_PAL8;
50 static int set_palette(BethsoftvidContext *ctx)
52 uint32_t *palette = (uint32_t *)ctx->frame.data[1];
55 if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
56 return AVERROR_INVALIDDATA;
58 for(a = 0; a < 256; a++){
59 palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
61 ctx->frame.palette_has_changed = 1;
65 static int bethsoftvid_decode_frame(AVCodecContext *avctx,
66 void *data, int *data_size,
69 BethsoftvidContext * vid = avctx->priv_data;
73 int remaining = avctx->width; // number of bytes remaining on a line
74 const int wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
78 if (avctx->reget_buffer(avctx, &vid->frame)) {
79 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
83 bytestream2_init(&vid->g, avpkt->data, avpkt->size);
84 dst = vid->frame.data[0];
85 frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
87 switch(block_type = bytestream2_get_byte(&vid->g)){
91 if ((ret = set_palette(vid)) < 0) {
92 av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
95 return bytestream2_tell(&vid->g);
97 case VIDEO_YOFF_P_FRAME:
98 yoffset = bytestream2_get_le16(&vid->g);
99 if(yoffset >= avctx->height)
101 dst += vid->frame.linesize[0] * yoffset;
105 while((code = bytestream2_get_byte(&vid->g))){
106 int length = code & 0x7f;
108 // copy any bytes starting at the current position, and ending at the frame width
109 while(length > remaining){
111 bytestream2_get_buffer(&vid->g, dst, remaining);
112 else if(block_type == VIDEO_I_FRAME)
113 memset(dst, bytestream2_peek_byte(&vid->g), remaining);
114 length -= remaining; // decrement the number of bytes to be copied
115 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
116 remaining = avctx->width;
121 // copy any remaining bytes after / if line overflows
123 bytestream2_get_buffer(&vid->g, dst, length);
124 else if(block_type == VIDEO_I_FRAME)
125 memset(dst, bytestream2_get_byte(&vid->g), length);
131 *data_size = sizeof(AVFrame);
132 *(AVFrame*)data = vid->frame;
137 static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
139 BethsoftvidContext * vid = avctx->priv_data;
140 if(vid->frame.data[0])
141 avctx->release_buffer(avctx, &vid->frame);
145 AVCodec ff_bethsoftvid_decoder = {
146 .name = "bethsoftvid",
147 .type = AVMEDIA_TYPE_VIDEO,
148 .id = CODEC_ID_BETHSOFTVID,
149 .priv_data_size = sizeof(BethsoftvidContext),
150 .init = bethsoftvid_decode_init,
151 .close = bethsoftvid_decode_end,
152 .decode = bethsoftvid_decode_frame,
153 .capabilities = CODEC_CAP_DR1,
154 .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),