1 /*
2 * Creative YUV (CYUV) Video Decoder
3 * by Mike Melanson (melanson@pcisys.net)
4 * based on "Creative YUV (CYUV) stream format for AVI":
5 * http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
6 *
7 * Copyright (c) 2003 The FFmpeg Project
8 *
9 * This file is part of FFmpeg.
10 *
11 * FFmpeg is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
15 *
16 * FFmpeg is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with FFmpeg; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26 /**
27 * @file
28 * Creative YUV (CYUV) Video Decoder.
29 */
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34
38
39
44
46 {
48
51 /* width needs to be divisible by 4 for this codec to work */
55
56 return 0;
57 }
58
60 void *
data,
int *got_frame,
62 {
64 int buf_size = avpkt->
size;
67
68 unsigned char *y_plane;
69 unsigned char *u_plane;
70 unsigned char *v_plane;
71 int y_ptr;
72 int u_ptr;
73 int v_ptr;
74
75 /* prediction error tables (make it clear that they are signed values) */
76 const signed char *y_table = (const signed char*)buf + 0;
77 const signed char *u_table = (const signed char*)buf + 16;
78 const signed char *v_table = (const signed char*)buf + 32;
79
80 unsigned char y_pred, u_pred, v_pred;
81 int stream_ptr;
82 unsigned char cur_byte;
83 int pixel_groups;
86
88 y_table = u_table;
89 u_table = v_table;
90 }
91 /* sanity check the buffer size: A buffer has 3x16-bytes tables
92 * followed by (height) lines each with 3 bytes to represent groups
93 * of 4 pixels. Thus, the total size of the buffer ought to be:
94 * (3 * 16) + height * (width * 3 / 4) */
95 if (buf_size == 48 + s->
height * (s->
width * 3 / 4)) {
97 } else if(buf_size == rawsize ) {
99 } else {
103 }
104
105 /* pixel data starts 48 bytes in, after 3x16-byte tables */
106 stream_ptr = 48;
107
110
111 y_plane = frame->
data[0];
112 u_plane = frame->
data[1];
113 v_plane = frame->
data[2];
114
115 if (buf_size == rawsize) {
118 for (stream_ptr = 0; stream_ptr < rawsize; stream_ptr += linesize) {
120 memcpy(y_plane, buf+stream_ptr, linesize);
121 }
122 } else {
123
124 /* iterate through each line in the height */
125 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
130
131 /* reset predictors */
132 cur_byte = buf[stream_ptr++];
133 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
134 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
135
136 cur_byte = buf[stream_ptr++];
137 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
138 y_pred += y_table[cur_byte & 0x0F];
139 y_plane[y_ptr++] = y_pred;
140
141 cur_byte = buf[stream_ptr++];
142 y_pred += y_table[cur_byte & 0x0F];
143 y_plane[y_ptr++] = y_pred;
144 y_pred += y_table[(cur_byte & 0xF0) >> 4];
145 y_plane[y_ptr++] = y_pred;
146
147 /* iterate through the remaining pixel groups (4 pixels/group) */
148 pixel_groups = s->
width / 4 - 1;
149 while (pixel_groups--) {
150
151 cur_byte = buf[stream_ptr++];
152 u_pred += u_table[(cur_byte & 0xF0) >> 4];
153 u_plane[u_ptr++] = u_pred;
154 y_pred += y_table[cur_byte & 0x0F];
155 y_plane[y_ptr++] = y_pred;
156
157 cur_byte = buf[stream_ptr++];
158 v_pred += v_table[(cur_byte & 0xF0) >> 4];
159 v_plane[v_ptr++] = v_pred;
160 y_pred += y_table[cur_byte & 0x0F];
161 y_plane[y_ptr++] = y_pred;
162
163 cur_byte = buf[stream_ptr++];
164 y_pred += y_table[cur_byte & 0x0F];
165 y_plane[y_ptr++] = y_pred;
166 y_pred += y_table[(cur_byte & 0xF0) >> 4];
167 y_plane[y_ptr++] = y_pred;
168
169 }
170 }
171 }
172
173 *got_frame = 1;
174
175 return buf_size;
176 }
177
178 #if CONFIG_AURA_DECODER
188 };
189 #endif
190
191 #if CONFIG_CYUV_DECODER
201 };
202 #endif