2 * Bethesda VID video decoder
3 * Copyright (C) 2007 Nicholas Tung
5 * This file is part of FFmpeg.
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.
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.
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
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"
36 typedef struct BethsoftvidContext {
41 static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
43 BethsoftvidContext *vid = avctx->priv_data;
44 avcodec_get_frame_defaults(&vid->frame);
45 avctx->pix_fmt = AV_PIX_FMT_PAL8;
49 static int set_palette(BethsoftvidContext *ctx)
51 uint32_t *palette = (uint32_t *)ctx->frame.data[1];
54 if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
55 return AVERROR_INVALIDDATA;
57 for(a = 0; a < 256; a++){
58 palette[a] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4;
59 palette[a] |= palette[a] >> 6 & 0x30303;
61 ctx->frame.palette_has_changed = 1;
65 static int bethsoftvid_decode_frame(AVCodecContext *avctx,
66 void *data, int *got_frame,
69 BethsoftvidContext * vid = avctx->priv_data;
73 int remaining = avctx->width; // number of bytes remaining on a line
74 int wrap_to_next_line;
78 if ((ret = ff_reget_buffer(avctx, &vid->frame)) < 0)
80 wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
82 if (avpkt->side_data_elems > 0 &&
83 avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
84 bytestream2_init(&vid->g, avpkt->side_data[0].data,
85 avpkt->side_data[0].size);
86 if ((ret = set_palette(vid)) < 0)
90 bytestream2_init(&vid->g, avpkt->data, avpkt->size);
91 dst = vid->frame.data[0];
92 frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
94 switch(block_type = bytestream2_get_byte(&vid->g)){
97 if ((ret = set_palette(vid)) < 0) {
98 av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
101 return bytestream2_tell(&vid->g);
103 case VIDEO_YOFF_P_FRAME:
104 yoffset = bytestream2_get_le16(&vid->g);
105 if(yoffset >= avctx->height)
106 return AVERROR_INVALIDDATA;
107 dst += vid->frame.linesize[0] * yoffset;
111 while((code = bytestream2_get_byte(&vid->g))){
112 int length = code & 0x7f;
114 // copy any bytes starting at the current position, and ending at the frame width
115 while(length > remaining){
117 bytestream2_get_buffer(&vid->g, dst, remaining);
118 else if(block_type == VIDEO_I_FRAME)
119 memset(dst, bytestream2_peek_byte(&vid->g), remaining);
120 length -= remaining; // decrement the number of bytes to be copied
121 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
122 remaining = avctx->width;
127 // copy any remaining bytes after / if line overflows
129 bytestream2_get_buffer(&vid->g, dst, length);
130 else if(block_type == VIDEO_I_FRAME)
131 memset(dst, bytestream2_get_byte(&vid->g), length);
137 if ((ret = av_frame_ref(data, &vid->frame)) < 0)
145 static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
147 BethsoftvidContext * vid = avctx->priv_data;
148 av_frame_unref(&vid->frame);
152 AVCodec ff_bethsoftvid_decoder = {
153 .name = "bethsoftvid",
154 .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
155 .type = AVMEDIA_TYPE_VIDEO,
156 .id = AV_CODEC_ID_BETHSOFTVID,
157 .priv_data_size = sizeof(BethsoftvidContext),
158 .init = bethsoftvid_decode_init,
159 .close = bethsoftvid_decode_end,
160 .decode = bethsoftvid_decode_frame,
161 .capabilities = CODEC_CAP_DR1,