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
7 * Copyright (c) 2003 The FFmpeg Project
9 * This file is part of FFmpeg.
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.
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.
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
28 * Creative YUV (CYUV) Video Decoder.
37 #include "libavutil/internal.h"
40 typedef struct CyuvDecodeContext
{
41 AVCodecContext
*avctx
;
45 static av_cold
int cyuv_decode_init(AVCodecContext
*avctx
)
47 CyuvDecodeContext
*s
= avctx
->priv_data
;
50 s
->width
= avctx
->width
;
51 /* width needs to be divisible by 4 for this codec to work */
53 return AVERROR_INVALIDDATA
;
54 s
->height
= avctx
->height
;
59 static int cyuv_decode_frame(AVCodecContext
*avctx
,
60 void *data
, int *got_frame
,
63 const uint8_t *buf
= avpkt
->data
;
64 int buf_size
= avpkt
->size
;
65 CyuvDecodeContext
*s
=avctx
->priv_data
;
66 AVFrame
*frame
= data
;
68 unsigned char *y_plane
;
69 unsigned char *u_plane
;
70 unsigned char *v_plane
;
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;
80 unsigned char y_pred
, u_pred
, v_pred
;
82 unsigned char cur_byte
;
84 int rawsize
= s
->height
* FFALIGN(s
->width
,2) * 2;
87 if (avctx
->codec_id
== AV_CODEC_ID_AURA
) {
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 avctx
->pix_fmt
= AV_PIX_FMT_YUV411P
;
97 } else if(buf_size
== rawsize
) {
98 avctx
->pix_fmt
= AV_PIX_FMT_UYVY422
;
100 av_log(avctx
, AV_LOG_ERROR
, "got a buffer with %d bytes when %d were expected\n",
101 buf_size
, 48 + s
->height
* (s
->width
* 3 / 4));
102 return AVERROR_INVALIDDATA
;
105 /* pixel data starts 48 bytes in, after 3x16-byte tables */
108 if ((ret
= ff_get_buffer(avctx
, frame
, 0)) < 0)
111 y_plane
= frame
->data
[0];
112 u_plane
= frame
->data
[1];
113 v_plane
= frame
->data
[2];
115 if (buf_size
== rawsize
) {
116 int linesize
= FFALIGN(s
->width
,2) * 2;
117 y_plane
+= frame
->linesize
[0] * s
->height
;
118 for (stream_ptr
= 0; stream_ptr
< rawsize
; stream_ptr
+= linesize
) {
119 y_plane
-= frame
->linesize
[0];
120 memcpy(y_plane
, buf
+stream_ptr
, linesize
);
124 /* iterate through each line in the height */
125 for (y_ptr
= 0, u_ptr
= 0, v_ptr
= 0;
126 y_ptr
< (s
->height
* frame
->linesize
[0]);
127 y_ptr
+= frame
->linesize
[0] - s
->width
,
128 u_ptr
+= frame
->linesize
[1] - s
->width
/ 4,
129 v_ptr
+= frame
->linesize
[2] - s
->width
/ 4) {
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;
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
;
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
;
147 /* iterate through the remaining pixel groups (4 pixels/group) */
148 pixel_groups
= s
->width
/ 4 - 1;
149 while (pixel_groups
--) {
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
;
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
;
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
;
178 #if CONFIG_AURA_DECODER
179 AVCodec ff_aura_decoder
= {
181 .long_name
= NULL_IF_CONFIG_SMALL("Auravision AURA"),
182 .type
= AVMEDIA_TYPE_VIDEO
,
183 .id
= AV_CODEC_ID_AURA
,
184 .priv_data_size
= sizeof(CyuvDecodeContext
),
185 .init
= cyuv_decode_init
,
186 .decode
= cyuv_decode_frame
,
187 .capabilities
= CODEC_CAP_DR1
,
191 #if CONFIG_CYUV_DECODER
192 AVCodec ff_cyuv_decoder
= {
194 .long_name
= NULL_IF_CONFIG_SMALL("Creative YUV (CYUV)"),
195 .type
= AVMEDIA_TYPE_VIDEO
,
196 .id
= AV_CODEC_ID_CYUV
,
197 .priv_data_size
= sizeof(CyuvDecodeContext
),
198 .init
= cyuv_decode_init
,
199 .decode
= cyuv_decode_frame
,
200 .capabilities
= CODEC_CAP_DR1
,