6b9d5b930785718e50dd41a805c40836934237ee
[libav.git] / libavcodec / cyuv.c
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 Libav.
10 *
11 * Libav 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 * Libav 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 Libav; 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
35 #include "avcodec.h"
36 #include "internal.h"
37 #include "libavutil/internal.h"
38
39
40 typedef struct CyuvDecodeContext {
41 AVCodecContext *avctx;
42 int width, height;
43 AVFrame frame;
44 } CyuvDecodeContext;
45
46 static av_cold int cyuv_decode_init(AVCodecContext *avctx)
47 {
48 CyuvDecodeContext *s = avctx->priv_data;
49
50 s->avctx = avctx;
51 s->width = avctx->width;
52 /* width needs to be divisible by 4 for this codec to work */
53 if (s->width & 0x3)
54 return AVERROR_INVALIDDATA;
55 s->height = avctx->height;
56 avctx->pix_fmt = AV_PIX_FMT_YUV411P;
57
58 return 0;
59 }
60
61 static int cyuv_decode_frame(AVCodecContext *avctx,
62 void *data, int *got_frame,
63 AVPacket *avpkt)
64 {
65 const uint8_t *buf = avpkt->data;
66 int buf_size = avpkt->size;
67 CyuvDecodeContext *s=avctx->priv_data;
68
69 unsigned char *y_plane;
70 unsigned char *u_plane;
71 unsigned char *v_plane;
72 int y_ptr;
73 int u_ptr;
74 int v_ptr;
75
76 /* prediction error tables (make it clear that they are signed values) */
77 const signed char *y_table = (const signed char*)buf + 0;
78 const signed char *u_table = (const signed char*)buf + 16;
79 const signed char *v_table = (const signed char*)buf + 32;
80
81 unsigned char y_pred, u_pred, v_pred;
82 int stream_ptr;
83 unsigned char cur_byte;
84 int pixel_groups;
85 int ret;
86
87 if (avctx->codec_id == AV_CODEC_ID_AURA) {
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)) {
96 av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
97 buf_size, 48 + s->height * (s->width * 3 / 4));
98 return AVERROR_INVALIDDATA;
99 }
100
101 /* pixel data starts 48 bytes in, after 3x16-byte tables */
102 stream_ptr = 48;
103
104 if (s->frame.data[0])
105 avctx->release_buffer(avctx, &s->frame);
106
107 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
108 s->frame.reference = 0;
109 if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
110 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
111 return ret;
112 }
113
114 y_plane = s->frame.data[0];
115 u_plane = s->frame.data[1];
116 v_plane = s->frame.data[2];
117
118 /* iterate through each line in the height */
119 for (y_ptr = 0, u_ptr = 0, v_ptr = 0;
120 y_ptr < (s->height * s->frame.linesize[0]);
121 y_ptr += s->frame.linesize[0] - s->width,
122 u_ptr += s->frame.linesize[1] - s->width / 4,
123 v_ptr += s->frame.linesize[2] - s->width / 4) {
124
125 /* reset predictors */
126 cur_byte = buf[stream_ptr++];
127 u_plane[u_ptr++] = u_pred = cur_byte & 0xF0;
128 y_plane[y_ptr++] = y_pred = (cur_byte & 0x0F) << 4;
129
130 cur_byte = buf[stream_ptr++];
131 v_plane[v_ptr++] = v_pred = cur_byte & 0xF0;
132 y_pred += y_table[cur_byte & 0x0F];
133 y_plane[y_ptr++] = y_pred;
134
135 cur_byte = buf[stream_ptr++];
136 y_pred += y_table[cur_byte & 0x0F];
137 y_plane[y_ptr++] = y_pred;
138 y_pred += y_table[(cur_byte & 0xF0) >> 4];
139 y_plane[y_ptr++] = y_pred;
140
141 /* iterate through the remaining pixel groups (4 pixels/group) */
142 pixel_groups = s->width / 4 - 1;
143 while (pixel_groups--) {
144
145 cur_byte = buf[stream_ptr++];
146 u_pred += u_table[(cur_byte & 0xF0) >> 4];
147 u_plane[u_ptr++] = u_pred;
148 y_pred += y_table[cur_byte & 0x0F];
149 y_plane[y_ptr++] = y_pred;
150
151 cur_byte = buf[stream_ptr++];
152 v_pred += v_table[(cur_byte & 0xF0) >> 4];
153 v_plane[v_ptr++] = v_pred;
154 y_pred += y_table[cur_byte & 0x0F];
155 y_plane[y_ptr++] = y_pred;
156
157 cur_byte = buf[stream_ptr++];
158 y_pred += y_table[cur_byte & 0x0F];
159 y_plane[y_ptr++] = y_pred;
160 y_pred += y_table[(cur_byte & 0xF0) >> 4];
161 y_plane[y_ptr++] = y_pred;
162
163 }
164 }
165
166 *got_frame = 1;
167 *(AVFrame*)data= s->frame;
168
169 return buf_size;
170 }
171
172 static av_cold int cyuv_decode_end(AVCodecContext *avctx)
173 {
174 CyuvDecodeContext *s = avctx->priv_data;
175
176 if (s->frame.data[0])
177 avctx->release_buffer(avctx, &s->frame);
178
179 return 0;
180 }
181
182 #if CONFIG_AURA_DECODER
183 AVCodec ff_aura_decoder = {
184 .name = "aura",
185 .type = AVMEDIA_TYPE_VIDEO,
186 .id = AV_CODEC_ID_AURA,
187 .priv_data_size = sizeof(CyuvDecodeContext),
188 .init = cyuv_decode_init,
189 .close = cyuv_decode_end,
190 .decode = cyuv_decode_frame,
191 .capabilities = CODEC_CAP_DR1,
192 .long_name = NULL_IF_CONFIG_SMALL("Auravision AURA"),
193 };
194 #endif
195
196 #if CONFIG_CYUV_DECODER
197 AVCodec ff_cyuv_decoder = {
198 .name = "cyuv",
199 .type = AVMEDIA_TYPE_VIDEO,
200 .id = AV_CODEC_ID_CYUV,
201 .priv_data_size = sizeof(CyuvDecodeContext),
202 .init = cyuv_decode_init,
203 .close = cyuv_decode_end,
204 .decode = cyuv_decode_frame,
205 .capabilities = CODEC_CAP_DR1,
206 .long_name = NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
207 };
208 #endif