ffmpeg / libavcodec / aura.c @ d36beb3f
History | View | Annotate | Download (3.75 KB)
1 |
/*
|
---|---|
2 |
* Aura 2 decoder
|
3 |
*
|
4 |
* This file is part of FFmpeg.
|
5 |
*
|
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.
|
10 |
*
|
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.
|
15 |
*
|
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
|
19 |
*/
|
20 |
|
21 |
/**
|
22 |
* @file
|
23 |
* Aura 2 decoder
|
24 |
*/
|
25 |
|
26 |
#include "avcodec.h" |
27 |
|
28 |
typedef struct AuraDecodeContext { |
29 |
AVCodecContext *avctx; |
30 |
AVFrame frame; |
31 |
} AuraDecodeContext; |
32 |
|
33 |
static av_cold int aura_decode_init(AVCodecContext *avctx) |
34 |
{ |
35 |
AuraDecodeContext *s = avctx->priv_data; |
36 |
|
37 |
s->avctx = avctx; |
38 |
/* width needs to be divisible by 4 for this codec to work */
|
39 |
if (avctx->width & 0x3) |
40 |
return -1; |
41 |
avctx->pix_fmt = PIX_FMT_YUV422P; |
42 |
|
43 |
return 0; |
44 |
} |
45 |
|
46 |
static int aura_decode_frame(AVCodecContext *avctx, |
47 |
void *data, int *data_size, |
48 |
AVPacket *pkt) |
49 |
{ |
50 |
AuraDecodeContext *s=avctx->priv_data; |
51 |
|
52 |
uint8_t *Y, *U, *V; |
53 |
uint8_t val; |
54 |
int x, y;
|
55 |
const uint8_t *buf = pkt->data;
|
56 |
|
57 |
/* prediction error tables (make it clear that they are signed values) */
|
58 |
const int8_t *delta_table = (const int8_t*)buf + 16; |
59 |
|
60 |
if (pkt->size != 48 + avctx->height * avctx->width) { |
61 |
av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
|
62 |
pkt->size, 48 + avctx->height * avctx->width);
|
63 |
return -1; |
64 |
} |
65 |
|
66 |
/* pixel data starts 48 bytes in, after 3x16-byte tables */
|
67 |
buf += 48;
|
68 |
|
69 |
if(s->frame.data[0]) |
70 |
avctx->release_buffer(avctx, &s->frame); |
71 |
|
72 |
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID; |
73 |
s->frame.reference = 0;
|
74 |
if(avctx->get_buffer(avctx, &s->frame) < 0) { |
75 |
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
|
76 |
return -1; |
77 |
} |
78 |
|
79 |
Y = s->frame.data[0];
|
80 |
U = s->frame.data[1];
|
81 |
V = s->frame.data[2];
|
82 |
|
83 |
/* iterate through each line in the height */
|
84 |
for (y = 0; y < avctx->height; y++) { |
85 |
/* reset predictors */
|
86 |
val = *buf++; |
87 |
U[0] = val & 0xF0; |
88 |
Y[0] = val << 4; |
89 |
val = *buf++; |
90 |
V[0] = val & 0xF0; |
91 |
Y[1] = Y[0] + delta_table[val & 0xF]; |
92 |
Y += 2; U++; V++;
|
93 |
|
94 |
/* iterate through the remaining pixel groups (4 pixels/group) */
|
95 |
for (x = 1; x < (avctx->width >> 1); x++) { |
96 |
val = *buf++; |
97 |
U[0] = U[-1] + delta_table[val >> 4]; |
98 |
Y[0] = Y[-1] + delta_table[val & 0xF]; |
99 |
val = *buf++; |
100 |
V[0] = V[-1] + delta_table[val >> 4]; |
101 |
Y[1] = Y[ 0] + delta_table[val & 0xF]; |
102 |
Y += 2; U++; V++;
|
103 |
} |
104 |
Y += s->frame.linesize[0] - avctx->width;
|
105 |
U += s->frame.linesize[1] - (avctx->width >> 1); |
106 |
V += s->frame.linesize[2] - (avctx->width >> 1); |
107 |
} |
108 |
|
109 |
*data_size=sizeof(AVFrame);
|
110 |
*(AVFrame*)data= s->frame; |
111 |
|
112 |
return pkt->size;
|
113 |
} |
114 |
|
115 |
static av_cold int aura_decode_end(AVCodecContext *avctx) |
116 |
{ |
117 |
AuraDecodeContext *s = avctx->priv_data; |
118 |
|
119 |
if (s->frame.data[0]) |
120 |
avctx->release_buffer(avctx, &s->frame); |
121 |
|
122 |
return 0; |
123 |
} |
124 |
|
125 |
AVCodec ff_aura2_decoder = { |
126 |
"aura2",
|
127 |
AVMEDIA_TYPE_VIDEO, |
128 |
CODEC_ID_AURA2, |
129 |
sizeof(AuraDecodeContext),
|
130 |
aura_decode_init, |
131 |
NULL,
|
132 |
aura_decode_end, |
133 |
aura_decode_frame, |
134 |
CODEC_CAP_DR1, |
135 |
NULL,
|
136 |
.long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
|
137 |
}; |
138 |
|