d0b34fdbe4287b8abd87f8d0e27ce2ff6de4205a
[libav.git] / libavcodec / bethsoftvideo.c
1 /*
2 * Bethesda VID video decoder
3 * Copyright (C) 2007 Nicholas Tung
4 *
5 * This file is part of Libav.
6 *
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.
11 *
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.
16 *
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
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
35 typedef struct BethsoftvidContext {
36 AVFrame frame;
37 GetByteContext g;
38 } BethsoftvidContext;
39
40 static av_cold int bethsoftvid_decode_init(AVCodecContext *avctx)
41 {
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 = AV_PIX_FMT_PAL8;
47 return 0;
48 }
49
50 static int set_palette(BethsoftvidContext *ctx)
51 {
52 uint32_t *palette = (uint32_t *)ctx->frame.data[1];
53 int a;
54
55 if (bytestream2_get_bytes_left(&ctx->g) < 256*3)
56 return AVERROR_INVALIDDATA;
57
58 for(a = 0; a < 256; a++){
59 palette[a] = bytestream2_get_be24u(&ctx->g) * 4;
60 }
61 ctx->frame.palette_has_changed = 1;
62 return 0;
63 }
64
65 static int bethsoftvid_decode_frame(AVCodecContext *avctx,
66 void *data, int *got_frame,
67 AVPacket *avpkt)
68 {
69 BethsoftvidContext * vid = avctx->priv_data;
70 char block_type;
71 uint8_t * dst;
72 uint8_t * frame_end;
73 int remaining = avctx->width; // number of bytes remaining on a line
74 int wrap_to_next_line;
75 int code, ret;
76 int yoffset;
77
78 if ((ret = avctx->reget_buffer(avctx, &vid->frame)) < 0) {
79 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
80 return ret;
81 }
82 wrap_to_next_line = vid->frame.linesize[0] - avctx->width;
83
84 if (avpkt->side_data_elems > 0 &&
85 avpkt->side_data[0].type == AV_PKT_DATA_PALETTE) {
86 bytestream2_init(&vid->g, avpkt->side_data[0].data,
87 avpkt->side_data[0].size);
88 if ((ret = set_palette(vid)) < 0)
89 return ret;
90 }
91
92 bytestream2_init(&vid->g, avpkt->data, avpkt->size);
93 dst = vid->frame.data[0];
94 frame_end = vid->frame.data[0] + vid->frame.linesize[0] * avctx->height;
95
96 switch(block_type = bytestream2_get_byte(&vid->g)){
97 case PALETTE_BLOCK: {
98 *got_frame = 0;
99 if ((ret = set_palette(vid)) < 0) {
100 av_log(avctx, AV_LOG_ERROR, "error reading palette\n");
101 return ret;
102 }
103 return bytestream2_tell(&vid->g);
104 }
105 case VIDEO_YOFF_P_FRAME:
106 yoffset = bytestream2_get_le16(&vid->g);
107 if(yoffset >= avctx->height)
108 return AVERROR_INVALIDDATA;
109 dst += vid->frame.linesize[0] * yoffset;
110 }
111
112 // main code
113 while((code = bytestream2_get_byte(&vid->g))){
114 int length = code & 0x7f;
115
116 // copy any bytes starting at the current position, and ending at the frame width
117 while(length > remaining){
118 if(code < 0x80)
119 bytestream2_get_buffer(&vid->g, dst, remaining);
120 else if(block_type == VIDEO_I_FRAME)
121 memset(dst, bytestream2_peek_byte(&vid->g), remaining);
122 length -= remaining; // decrement the number of bytes to be copied
123 dst += remaining + wrap_to_next_line; // skip over extra bytes at end of frame
124 remaining = avctx->width;
125 if(dst == frame_end)
126 goto end;
127 }
128
129 // copy any remaining bytes after / if line overflows
130 if(code < 0x80)
131 bytestream2_get_buffer(&vid->g, dst, length);
132 else if(block_type == VIDEO_I_FRAME)
133 memset(dst, bytestream2_get_byte(&vid->g), length);
134 remaining -= length;
135 dst += length;
136 }
137 end:
138
139 *got_frame = 1;
140 *(AVFrame*)data = vid->frame;
141
142 return avpkt->size;
143 }
144
145 static av_cold int bethsoftvid_decode_end(AVCodecContext *avctx)
146 {
147 BethsoftvidContext * vid = avctx->priv_data;
148 if(vid->frame.data[0])
149 avctx->release_buffer(avctx, &vid->frame);
150 return 0;
151 }
152
153 AVCodec ff_bethsoftvid_decoder = {
154 .name = "bethsoftvid",
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,
162 .long_name = NULL_IF_CONFIG_SMALL("Bethesda VID video"),
163 };