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aura.c
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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 
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  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 
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 };
const char const char void * val
Definition: avisynth_c.h:634
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static av_cold int aura_decode_init(AVCodecContext *avctx)
Definition: aura.c:30
int size
Definition: avcodec.h:1578
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1870
static AVPacket pkt
AVCodec ff_aura2_decoder
Definition: aura.c:100
AVCodec.
Definition: avcodec.h:3535
uint8_t
#define av_cold
Definition: attributes.h:82
#define Y
Definition: vf_boxblur.c:76
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1577
#define av_log(a,...)
#define U(x)
Definition: vp56_arith.h:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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:176
const char * name
Name of the codec implementation.
Definition: avcodec.h:3542
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:66
common internal API header
int width
picture width / height.
Definition: avcodec.h:1829
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:211
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:1642
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:928
void * buf
Definition: avisynth_c.h:553
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:194
common internal api header.
This structure stores compressed data.
Definition: avcodec.h:1554
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:953
#define V
Definition: avdct.c:30