Libav
aura.c
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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 
26 #include "avcodec.h"
27 #include "internal.h"
28 #include "libavutil/internal.h"
29 
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 
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 
103  .name = "aura2",
104  .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
105  .type = AVMEDIA_TYPE_VIDEO,
106  .id = AV_CODEC_ID_AURA2,
107  .init = aura_decode_init,
108  .decode = aura_decode_frame,
109  .capabilities = CODEC_CAP_DR1,
110 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
static av_cold int aura_decode_init(AVCodecContext *avctx)
Definition: aura.c:30
int size
Definition: avcodec.h:974
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1270
AVCodec ff_aura2_decoder
Definition: aura.c:102
AVCodec.
Definition: avcodec.h:2812
uint8_t
#define av_cold
Definition: attributes.h:66
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:973
Definition: vf_drawbox.c:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2819
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:69
common internal API header
#define V
Definition: options_table.h:35
int width
picture width / height.
Definition: avcodec.h:1229
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
static int aura_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *pkt)
Definition: aura.c:40
main external API structure.
Definition: avcodec.h:1050
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:612
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
common internal api header.
This structure stores compressed data.
Definition: avcodec.h:950
Definition: vf_drawbox.c:37