blob: 5ef9316632ada2552f293714e88bcb9f007c4bcd
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 | #include "internal.h" |
28 | #include "libavutil/internal.h" |
29 | |
30 | static av_cold int aura_decode_init(AVCodecContext *avctx) |
31 | { |
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; |
36 | |
37 | return 0; |
38 | } |
39 | |
40 | static int aura_decode_frame(AVCodecContext *avctx, |
41 | void *data, int *got_frame, |
42 | AVPacket *pkt) |
43 | { |
44 | AVFrame *frame = data; |
45 | uint8_t *Y, *U, *V; |
46 | uint8_t val; |
47 | int x, y, ret; |
48 | const uint8_t *buf = pkt->data; |
49 | |
50 | /* prediction error tables (make it clear that they are signed values) */ |
51 | const int8_t *delta_table = (const int8_t*)buf + 16; |
52 | |
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; |
57 | } |
58 | |
59 | /* pixel data starts 48 bytes in, after 3x16-byte tables */ |
60 | buf += 48; |
61 | |
62 | if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) |
63 | return ret; |
64 | |
65 | Y = frame->data[0]; |
66 | U = frame->data[1]; |
67 | V = frame->data[2]; |
68 | |
69 | /* iterate through each line in the height */ |
70 | for (y = 0; y < avctx->height; y++) { |
71 | /* reset predictors */ |
72 | val = *buf++; |
73 | U[0] = val & 0xF0; |
74 | Y[0] = val << 4; |
75 | val = *buf++; |
76 | V[0] = val & 0xF0; |
77 | Y[1] = Y[0] + delta_table[val & 0xF]; |
78 | Y += 2; U++; V++; |
79 | |
80 | /* iterate through the remaining pixel groups (4 pixels/group) */ |
81 | for (x = 1; x < (avctx->width >> 1); x++) { |
82 | val = *buf++; |
83 | U[0] = U[-1] + delta_table[val >> 4]; |
84 | Y[0] = Y[-1] + delta_table[val & 0xF]; |
85 | val = *buf++; |
86 | V[0] = V[-1] + delta_table[val >> 4]; |
87 | Y[1] = Y[ 0] + delta_table[val & 0xF]; |
88 | Y += 2; U++; V++; |
89 | } |
90 | Y += frame->linesize[0] - avctx->width; |
91 | U += frame->linesize[1] - (avctx->width >> 1); |
92 | V += frame->linesize[2] - (avctx->width >> 1); |
93 | } |
94 | |
95 | *got_frame = 1; |
96 | |
97 | return pkt->size; |
98 | } |
99 | |
100 | AVCodec ff_aura2_decoder = { |
101 | .name = "aura2", |
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 = AV_CODEC_CAP_DR1, |
108 | .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE, |
109 | }; |
110 |