lavc decoders: work with refcounted frames.
[libav.git] / libavcodec / aura.c
1 /*
2 * Aura 2 decoder
3 *
4 * This file is part of Libav.
5 *
6 * Libav 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 * Libav 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 Libav; 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 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
64 return ret;
65 }
66
67 Y = frame->data[0];
68 U = frame->data[1];
69 V = frame->data[2];
70
71 /* iterate through each line in the height */
72 for (y = 0; y < avctx->height; y++) {
73 /* reset predictors */
74 val = *buf++;
75 U[0] = val & 0xF0;
76 Y[0] = val << 4;
77 val = *buf++;
78 V[0] = val & 0xF0;
79 Y[1] = Y[0] + delta_table[val & 0xF];
80 Y += 2; U++; V++;
81
82 /* iterate through the remaining pixel groups (4 pixels/group) */
83 for (x = 1; x < (avctx->width >> 1); x++) {
84 val = *buf++;
85 U[0] = U[-1] + delta_table[val >> 4];
86 Y[0] = Y[-1] + delta_table[val & 0xF];
87 val = *buf++;
88 V[0] = V[-1] + delta_table[val >> 4];
89 Y[1] = Y[ 0] + delta_table[val & 0xF];
90 Y += 2; U++; V++;
91 }
92 Y += frame->linesize[0] - avctx->width;
93 U += frame->linesize[1] - (avctx->width >> 1);
94 V += frame->linesize[2] - (avctx->width >> 1);
95 }
96
97 *got_frame = 1;
98
99 return pkt->size;
100 }
101
102 AVCodec ff_aura2_decoder = {
103 .name = "aura2",
104 .type = AVMEDIA_TYPE_VIDEO,
105 .id = AV_CODEC_ID_AURA2,
106 .init = aura_decode_init,
107 .decode = aura_decode_frame,
108 .capabilities = CODEC_CAP_DR1,
109 .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
110 };