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 * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27 * @see http://www.svatopluk.com/andux/docs/dfvid.html
28 */
29
30 #include "libavutil/common.h"
31 #include "avcodec.h"
32 #include "bethsoftvideo.h"
33 #include "bytestream.h"
34 #include "codec_internal.h"
35 #include "internal.h"
36
37 typedef struct BethsoftvidContext {
38 AVFrame *frame;
39 GetByteContext g;
40 } BethsoftvidContext;
41
bethsoftvid_decode_init(AVCodecContext *avctx)42 static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
43 {
44 BethsoftvidContext *vid = avctx->priv_data;
45 avctx->pix_fmt = AV_PIX_FMT_PAL8;
46
47 vid->frame = av_frame_alloc();
48 if (!vid->frame)
49 return AVERROR(ENOMEM);
50
51 return 0;
52 }
53
set_palette(BethsoftvidContext *ctx)54 static int set_palette(BethsoftvidContext *ctx)
55 {
56 uint32_t *palette = (uint32_t *)ctx->frame->data[1];
57 int a;
58
59 if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
60 return AVERROR_INVALIDDATA;
61
62 for(a = 0; a < 256; a++){
63 palette[a] = 0xFFU << 24 | bytestream2_get_be24u(&ctx->g) * 4;
64 palette[a] |= palette[a] >> 6 & 0x30303;
65 }
66 ctx->frame->palette_has_changed = 1;
67 return 0;
68 }
69
bethsoftvid_decode_frame(AVCodecContext *avctx, AVFrame *rframe, int *got_frame, AVPacket *avpkt)70 static int bethsoftvid_decode_frame(AVCodecContext *avctx, AVFrame *rframe,
71 int *got_frame, AVPacket *avpkt)
72 {
73 BethsoftvidContext * vid = avctx->priv_data;
74 char block_type;
75 uint8_t * dst;
76 uint8_t * frame_end;
77 int remaining = avctx->width; // number of bytes remaining on a line
78 int wrap_to_next_line;
79 int code, ret;
80 int yoffset;
81
82 if ((ret = ff_reget_buffer(avctx, vid->frame, 0)) < 0)
83 return ret;
84 wrap_to_next_line = vid->frame->linesize[0] - avctx->width;
85
86 if (avpkt->side_data_elems > 0 &&
87 avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
88 bytestream2_init(&vid->g, avpkt->side_data[0].data,
89 avpkt->side_data[0].size);
90 if ((ret = set_palette(vid)) < 0)
91 return ret;
92 }
93
94 bytestream2_init(&vid->g, avpkt->data, avpkt->size);
95 dst = vid->frame->data[0];
96 frame_end = vid->frame->data[0] + vid->frame->linesize[0] * avctx->height;
97
98 switch(block_type = bytestream2_get_byte(&vid->g)){
99 case PALETTE_BLOCK: {
100 *got_frame = 0;
101 if ((ret = set_palette(vid)) < 0) {
102 av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
103 return ret;
104 }
105 return bytestream2_tell(&vid->g);
106 }
107 case VIDEO_YOFF_P_FRAME:
108 yoffset = bytestream2_get_le16(&vid->g);
109 if(yoffset >= avctx->height)
110 return AVERROR_INVALIDDATA;
111 dst += vid->frame->linesize[0] * yoffset;
112 case VIDEO_P_FRAME:
113 case VIDEO_I_FRAME:
114 break;
115 default:
116 return AVERROR_INVALIDDATA;
117 }
118
119 // main code
120 while((code = bytestream2_get_byte(&vid->g))){
121 int length = code & 0x7f;
122
123 // copy any bytes starting at the current position, and ending at the frame width
124 while(length > remaining){
125 if(code < 0x80)
126 bytestream2_get_buffer(&vid->g, dst, remaining);
127 else if(block_type == VIDEO_I_FRAME)
128 memset(dst, bytestream2_peek_byte(&vid->g), remaining);
129 length -= remaining; // decrement the number of bytes to be copied
130 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
131 remaining = avctx->width;
132 if(dst == frame_end)
133 goto end;
134 }
135
136 // copy any remaining bytes after / if line overflows
137 if(code < 0x80)
138 bytestream2_get_buffer(&vid->g, dst, length);
139 else if(block_type == VIDEO_I_FRAME)
140 memset(dst, bytestream2_get_byte(&vid->g), length);
141 remaining -= length;
142 dst += length;
143 }
144 end:
145
146 if ((ret = av_frame_ref(rframe, vid->frame)) < 0)
147 return ret;
148
149 *got_frame = 1;
150
151 return avpkt->size;
152 }
153
bethsoftvid_decode_end(AVCodecContext *avctx)154 static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
155 {
156 BethsoftvidContext * vid = avctx->priv_data;
157 av_frame_free(&vid->frame);
158 return 0;
159 }
160
161 const FFCodec ff_bethsoftvid_decoder = {
162 .p.name = "bethsoftvid",
163 .p.long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
164 .p.type = AVMEDIA_TYPE_VIDEO,
165 .p.id = AV_CODEC_ID_BETHSOFTVID,
166 .priv_data_size = sizeof(BethsoftvidContext),
167 .init = bethsoftvid_decode_init,
168 .close = bethsoftvid_decode_end,
169 FF_CODEC_DECODE_CB(bethsoftvid_decode_frame),
170 .p.capabilities = AV_CODEC_CAP_DR1,
171 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
172 };
173