lavc: fix decode_frame() third parameter semantics for video decoders
[libav.git] / libavcodec / bfi.c
1 /*
2 * Brute Force & Ignorance (BFI) video decoder
3 * Copyright (c) 2008 Sisir Koppaka
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 Brute Force & Ignorance (.bfi) video decoder
25 * @author Sisir Koppaka ( sisir.koppaka at gmail dot com )
26 * @see http://wiki.multimedia.cx/index.php?title=BFI
27 */
28
29 #include "libavutil/common.h"
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "internal.h"
33
34 typedef struct BFIContext {
35 AVCodecContext *avctx;
36 AVFrame frame;
37 uint8_t *dst;
38 } BFIContext;
39
40 static av_cold int bfi_decode_init(AVCodecContext *avctx)
41 {
42 BFIContext *bfi = avctx->priv_data;
43 avctx->pix_fmt = AV_PIX_FMT_PAL8;
44 bfi->dst = av_mallocz(avctx->width * avctx->height);
45 return 0;
46 }
47
48 static int bfi_decode_frame(AVCodecContext *avctx, void *data,
49 int *got_frame, AVPacket *avpkt)
50 {
51 GetByteContext g;
52 int buf_size = avpkt->size;
53 BFIContext *bfi = avctx->priv_data;
54 uint8_t *dst = bfi->dst;
55 uint8_t *src, *dst_offset, colour1, colour2;
56 uint8_t *frame_end = bfi->dst + avctx->width * avctx->height;
57 uint32_t *pal;
58 int i, j, height = avctx->height;
59
60 if (bfi->frame.data[0])
61 avctx->release_buffer(avctx, &bfi->frame);
62
63 bfi->frame.reference = 1;
64
65 if (ff_get_buffer(avctx, &bfi->frame) < 0) {
66 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
67 return -1;
68 }
69
70 bytestream2_init(&g, avpkt->data, buf_size);
71
72 /* Set frame parameters and palette, if necessary */
73 if (!avctx->frame_number) {
74 bfi->frame.pict_type = AV_PICTURE_TYPE_I;
75 bfi->frame.key_frame = 1;
76 /* Setting the palette */
77 if (avctx->extradata_size > 768) {
78 av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
79 return -1;
80 }
81 pal = (uint32_t *)bfi->frame.data[1];
82 for (i = 0; i < avctx->extradata_size / 3; i++) {
83 int shift = 16;
84 *pal = 0;
85 for (j = 0; j < 3; j++, shift -= 8)
86 *pal += ((avctx->extradata[i * 3 + j] << 2) |
87 (avctx->extradata[i * 3 + j] >> 4)) << shift;
88 pal++;
89 }
90 bfi->frame.palette_has_changed = 1;
91 } else {
92 bfi->frame.pict_type = AV_PICTURE_TYPE_P;
93 bfi->frame.key_frame = 0;
94 }
95
96 bytestream2_skip(&g, 4); // Unpacked size, not required.
97
98 while (dst != frame_end) {
99 static const uint8_t lentab[4] = { 0, 2, 0, 1 };
100 unsigned int byte = bytestream2_get_byte(&g), av_uninit(offset);
101 unsigned int code = byte >> 6;
102 unsigned int length = byte & ~0xC0;
103
104 if (!bytestream2_get_bytes_left(&g)) {
105 av_log(avctx, AV_LOG_ERROR,
106 "Input resolution larger than actual frame.\n");
107 return -1;
108 }
109
110 /* Get length and offset (if required) */
111 if (length == 0) {
112 if (code == 1) {
113 length = bytestream2_get_byte(&g);
114 offset = bytestream2_get_le16(&g);
115 } else {
116 length = bytestream2_get_le16(&g);
117 if (code == 2 && length == 0)
118 break;
119 }
120 } else {
121 if (code == 1)
122 offset = bytestream2_get_byte(&g);
123 }
124
125 /* Do boundary check */
126 if (dst + (length << lentab[code]) > frame_end)
127 break;
128
129 switch (code) {
130 case 0: // normal chain
131 if (length >= bytestream2_get_bytes_left(&g)) {
132 av_log(avctx, AV_LOG_ERROR, "Frame larger than buffer.\n");
133 return -1;
134 }
135 bytestream2_get_buffer(&g, dst, length);
136 dst += length;
137 break;
138 case 1: // back chain
139 dst_offset = dst - offset;
140 length *= 4; // Convert dwords to bytes.
141 if (dst_offset < bfi->dst)
142 break;
143 while (length--)
144 *dst++ = *dst_offset++;
145 break;
146 case 2: // skip chain
147 dst += length;
148 break;
149 case 3: // fill chain
150 colour1 = bytestream2_get_byte(&g);
151 colour2 = bytestream2_get_byte(&g);
152 while (length--) {
153 *dst++ = colour1;
154 *dst++ = colour2;
155 }
156 break;
157 }
158 }
159
160 src = bfi->dst;
161 dst = bfi->frame.data[0];
162 while (height--) {
163 memcpy(dst, src, avctx->width);
164 src += avctx->width;
165 dst += bfi->frame.linesize[0];
166 }
167 *got_frame = 1;
168 *(AVFrame *)data = bfi->frame;
169 return buf_size;
170 }
171
172 static av_cold int bfi_decode_close(AVCodecContext *avctx)
173 {
174 BFIContext *bfi = avctx->priv_data;
175 if (bfi->frame.data[0])
176 avctx->release_buffer(avctx, &bfi->frame);
177 av_free(bfi->dst);
178 return 0;
179 }
180
181 AVCodec ff_bfi_decoder = {
182 .name = "bfi",
183 .type = AVMEDIA_TYPE_VIDEO,
184 .id = AV_CODEC_ID_BFI,
185 .priv_data_size = sizeof(BFIContext),
186 .init = bfi_decode_init,
187 .close = bfi_decode_close,
188 .decode = bfi_decode_frame,
189 .capabilities = CODEC_CAP_DR1,
190 .long_name = NULL_IF_CONFIG_SMALL("Brute Force & Ignorance"),
191 };