release buffer cleanup
[libav.git] / libavcodec / cyuv.c
1 /*
2 *
3 * Copyright (C) 2003 the ffmpeg project
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 *
19 * Creative YUV (CYUV) Video Decoder
20 * by Mike Melanson (melanson@pcisys.net)
21 * based on "Creative YUV (CYUV) stream format for AVI":
22 * http://www.csse.monash.edu.au/~timf/videocodec/cyuv.txt
23 *
24 */
25
26 /**
27 * @file cyuv.c
28 * Creative YUV (CYUV) Video Decoder.
29 */
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35
36 #include "common.h"
37 #include "avcodec.h"
38 #include "dsputil.h"
39 #include "mpegvideo.h"
40 #include "bswap.h"
41
42
43 typedef struct CyuvDecodeContext {
44 AVCodecContext *avctx;
45 int width, height;
46 AVFrame frame;
47 } CyuvDecodeContext;
48
49 static int cyuv_decode_init(AVCodecContext *avctx)
50 {
51 CyuvDecodeContext *s = avctx->priv_data;
52
53 s->avctx = avctx;
54 s->width = avctx->width;
55 s->height = avctx->height;
56 avctx->pix_fmt = PIX_FMT_YUV411P;
57 avctx->has_b_frames = 0;
58
59 return 0;
60 }
61
62 static int cyuv_decode_frame(AVCodecContext *avctx,
63 void *data, int *data_size,
64 uint8_t *buf, int buf_size)
65 {
66 CyuvDecodeContext *s=avctx->priv_data;
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 signed char *y_table = buf + 0;
77 signed char *u_table = buf + 16;
78 signed char *v_table = 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;
84
85 *data_size = 0;
86
87 /* sanity check the buffer size: A buffer has 3x16-bytes tables
88 * followed by (height) lines each with 3 bytes to represent groups
89 * of 4 pixels. Thus, the total size of the buffer ought to be:
90 * (3 * 16) + height * (width * 3 / 4) */
91 if (buf_size != 48 + s->height * (s->width * 3 / 4)) {
92 printf ("ffmpeg: cyuv: got a buffer with %d bytes when %d were expected\n",
93 buf_size,
94 48 + s->height * (s->width * 3 / 4));
95 return -1;
96 }
97
98 /* pixel data starts 48 bytes in, after 3x16-byte tables */
99 stream_ptr = 48;
100
101 if(s->frame.data[0])
102 avctx->release_buffer(avctx, &s->frame);
103
104 s->frame.reference = 0;
105 if(avctx->get_buffer(avctx, &s->frame) < 0) {
106 fprintf(stderr, "get_buffer() failed\n");
107 return -1;
108 }
109
110 y_plane = s->frame.data[0];
111 u_plane = s->frame.data[1];
112 v_plane = s->frame.data[2];
113
114 /* iterate through each line in the height */
115 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
116 y_ptr < (s->height * s->frame.linesize[0]);
117 y_ptr += s->frame.linesize[0] - s->width,
118 u_ptr += s->frame.linesize[1] - s->width / 4,
119 v_ptr += s->frame.linesize[2] - s->width / 4) {
120
121 /* reset predictors */
122 cur_byte = buf[stream_ptr++];
123 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
124 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
125
126 cur_byte = buf[stream_ptr++];
127 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
128 y_pred += y_table[cur_byte & 0x0F];
129 y_plane[y_ptr++] = y_pred;
130
131 cur_byte = buf[stream_ptr++];
132 y_pred += y_table[cur_byte & 0x0F];
133 y_plane[y_ptr++] = y_pred;
134 y_pred += y_table[(cur_byte & 0xF0) >> 4];
135 y_plane[y_ptr++] = y_pred;
136
137 /* iterate through the remaining pixel groups (4 pixels/group) */
138 pixel_groups = s->width / 4 - 1;
139 while (pixel_groups--) {
140
141 cur_byte = buf[stream_ptr++];
142 u_pred += u_table[(cur_byte & 0xF0) >> 4];
143 u_plane[u_ptr++] = u_pred;
144 y_pred += y_table[cur_byte & 0x0F];
145 y_plane[y_ptr++] = y_pred;
146
147 cur_byte = buf[stream_ptr++];
148 v_pred += v_table[(cur_byte & 0xF0) >> 4];
149 v_plane[v_ptr++] = v_pred;
150 y_pred += y_table[cur_byte & 0x0F];
151 y_plane[y_ptr++] = y_pred;
152
153 cur_byte = buf[stream_ptr++];
154 y_pred += y_table[cur_byte & 0x0F];
155 y_plane[y_ptr++] = y_pred;
156 y_pred += y_table[(cur_byte & 0xF0) >> 4];
157 y_plane[y_ptr++] = y_pred;
158
159 }
160 }
161
162 *data_size=sizeof(AVFrame);
163 *(AVFrame*)data= s->frame;
164
165 return buf_size;
166 }
167
168 static int cyuv_decode_end(AVCodecContext *avctx)
169 {
170 /* CyuvDecodeContext *s = avctx->priv_data;*/
171
172 return 0;
173 }
174
175 AVCodec cyuv_decoder = {
176 "cyuv",
177 CODEC_TYPE_VIDEO,
178 CODEC_ID_CYUV,
179 sizeof(CyuvDecodeContext),
180 cyuv_decode_init,
181 NULL,
182 cyuv_decode_end,
183 cyuv_decode_frame,
184 0,
185 NULL
186 };
187