4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28 #include "libavutil/internal.h"
30 static av_cold
int aura_decode_init(AVCodecContext
*avctx
)
32 /* width needs to be divisible by 4 for this codec to work */
33 if (avctx
->width
& 0x3)
34 return AVERROR(EINVAL
);
35 avctx
->pix_fmt
= AV_PIX_FMT_YUV422P
;
40 static int aura_decode_frame(AVCodecContext
*avctx
,
41 void *data
, int *got_frame
,
44 AVFrame
*frame
= data
;
48 const uint8_t *buf
= pkt
->data
;
50 /* prediction error tables (make it clear that they are signed values) */
51 const int8_t *delta_table
= (const int8_t*)buf
+ 16;
53 if (pkt
->size
!= 48 + avctx
->height
* avctx
->width
) {
54 av_log(avctx
, AV_LOG_ERROR
, "got a buffer with %d bytes when %d were expected\n",
55 pkt
->size
, 48 + avctx
->height
* avctx
->width
);
56 return AVERROR_INVALIDDATA
;
59 /* pixel data starts 48 bytes in, after 3x16-byte tables */
62 if ((ret
= ff_get_buffer(avctx
, frame
, 0)) < 0)
69 /* iterate through each line in the height */
70 for (y
= 0; y
< avctx
->height
; y
++) {
71 /* reset predictors */
77 Y
[1] = Y
[0] + delta_table
[val
& 0xF];
80 /* iterate through the remaining pixel groups (4 pixels/group) */
81 for (x
= 1; x
< (avctx
->width
>> 1); x
++) {
83 U
[0] = U
[-1] + delta_table
[val
>> 4];
84 Y
[0] = Y
[-1] + delta_table
[val
& 0xF];
86 V
[0] = V
[-1] + delta_table
[val
>> 4];
87 Y
[1] = Y
[ 0] + delta_table
[val
& 0xF];
90 Y
+= frame
->linesize
[0] - avctx
->width
;
91 U
+= frame
->linesize
[1] - (avctx
->width
>> 1);
92 V
+= frame
->linesize
[2] - (avctx
->width
>> 1);
100 AVCodec ff_aura2_decoder
= {
102 .long_name
= NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
103 .type
= AVMEDIA_TYPE_VIDEO
,
104 .id
= AV_CODEC_ID_AURA2
,
105 .init
= aura_decode_init
,
106 .decode
= aura_decode_frame
,
107 .capabilities
= CODEC_CAP_DR1
,