Rename var: val -> energy
[FFMpeg-mirror/DVCPRO-HD.git] / libavcodec / bfi.c
blobc3f23000045d82a0dec3331384af204aebd046a3
1 /*
2 * Brute Force & Ignorance (BFI) video decoder
3 * Copyright (c) 2008 Sisir Koppaka
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
22 /**
23 * @file bfi.c
24 * @brief Brute Force & Ignorance (.bfi) video decoder
25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26 * @sa http://wiki.multimedia.cx/index.php?title=BFI
29 #include "libavutil/common.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
33 typedef struct BFIContext {
34 AVCodecContext *avctx;
35 AVFrame frame;
36 uint8_t *dst;
37 } BFIContext;
39 static int bfi_decode_init(AVCodecContext * avctx)
41 BFIContext *bfi = avctx->priv_data;
42 avctx->pix_fmt = PIX_FMT_PAL8;
43 bfi->dst = av_mallocz(avctx->width * avctx->height);
44 return 0;
47 static int bfi_decode_frame(AVCodecContext * avctx, void *data,
48 int *data_size, const uint8_t * buf,
49 int buf_size)
51 BFIContext *bfi = avctx->priv_data;
52 uint8_t *dst = bfi->dst;
53 uint8_t *src, *dst_offset, colour1, colour2;
54 uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
55 uint32_t *pal;
56 int i, j, height = avctx->height;
58 if (bfi->frame.data[0])
59 avctx->release_buffer(avctx, &bfi->frame);
61 bfi->frame.reference = 1;
63 if (avctx->get_buffer(avctx, &bfi->frame) < 0) {
64 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
65 return -1;
68 /* Set frame parameters and palette, if necessary */
69 if (!avctx->frame_number) {
70 bfi->frame.pict_type = FF_I_TYPE;
71 bfi->frame.key_frame = 1;
72 /* Setting the palette */
73 if(avctx->extradata_size>768) {
74 av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
75 return -1;
77 pal = (uint32_t *) bfi->frame.data[1];
78 for (i = 0; i < avctx->extradata_size / 3; i++) {
79 int shift = 16;
80 *pal = 0;
81 for (j = 0; j < 3; j++, shift -= 8)
82 *pal +=
83 ((avctx->extradata[i * 3 + j] << 2) |
84 (avctx->extradata[i * 3 + j] >> 4)) << shift;
85 pal++;
87 bfi->frame.palette_has_changed = 1;
88 } else {
89 bfi->frame.pict_type = FF_P_TYPE;
90 bfi->frame.key_frame = 0;
93 buf += 4; //Unpacked size, not required.
95 while (dst != frame_end) {
96 static const uint8_t lentab[4]={0,2,0,1};
97 unsigned int byte = *buf++, offset;
98 unsigned int code = byte >> 6;
99 unsigned int length = byte & ~0xC0;
101 /* Get length and offset(if required) */
102 if (length == 0) {
103 if (code == 1) {
104 length = bytestream_get_byte(&buf);
105 offset = bytestream_get_le16(&buf);
106 } else {
107 length = bytestream_get_le16(&buf);
108 if (code == 2 && length == 0)
109 break;
111 } else {
112 if (code == 1)
113 offset = bytestream_get_byte(&buf);
116 /* Do boundary check */
117 if (dst + (length<<lentab[code]) > frame_end)
118 break;
120 switch (code) {
122 case 0: //Normal Chain
123 bytestream_get_buffer(&buf, dst, length);
124 dst += length;
125 break;
127 case 1: //Back Chain
128 dst_offset = dst - offset;
129 length *= 4; //Convert dwords to bytes.
130 if (dst_offset < bfi->dst)
131 break;
132 while (length--)
133 *dst++ = *dst_offset++;
134 break;
136 case 2: //Skip Chain
137 dst += length;
138 break;
140 case 3: //Fill Chain
141 colour1 = bytestream_get_byte(&buf);
142 colour2 = bytestream_get_byte(&buf);
143 while (length--) {
144 *dst++ = colour1;
145 *dst++ = colour2;
147 break;
152 src = bfi->dst;
153 dst = bfi->frame.data[0];
154 while (height--) {
155 memcpy(dst, src, avctx->width);
156 src += avctx->width;
157 dst += bfi->frame.linesize[0];
159 *data_size = sizeof(AVFrame);
160 *(AVFrame *) data = bfi->frame;
161 return buf_size;
164 static int bfi_decode_close(AVCodecContext * avctx)
166 BFIContext *bfi = avctx->priv_data;
167 if (bfi->frame.data[0])
168 avctx->release_buffer(avctx, &bfi->frame);
169 av_free(bfi->dst);
170 return 0;
173 AVCodec bfi_decoder = {
174 .name = "bfi",
175 .type = CODEC_TYPE_VIDEO,
176 .id = CODEC_ID_BFI,
177 .priv_data_size = sizeof(BFIContext),
178 .init = bfi_decode_init,
179 .close = bfi_decode_close,
180 .decode = bfi_decode_frame,
181 .long_name = "Brute Force & Ignorance",