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 
28 typedef struct AuraDecodeContext {
32 
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 
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 
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 
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 
126  .name = "aura2",
127  .type = AVMEDIA_TYPE_VIDEO,
128  .id = CODEC_ID_AURA2,
129  .priv_data_size = sizeof(AuraDecodeContext),
133  .capabilities = CODEC_CAP_DR1,
134  .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
135 };
136 
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:68
int(* get_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called at the beginning of each frame to get a buffer for it.
Definition: avcodec.h:1726
enum PixelFormat pix_fmt
Pixel format, see PIX_FMT_xxx.
Definition: avcodec.h:1426
AVFrame frame
Definition: aura.c:30
#define FF_BUFFER_HINTS_VALID
Definition: avcodec.h:880
Audio Video Frame.
Definition: avcodec.h:985
static av_cold int aura_decode_init(AVCodecContext *avctx)
Definition: aura.c:33
int buffer_hints
codec suggestion on buffer type if != 0
Definition: avcodec.h:1195
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:1737
static int aura_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt)
Definition: aura.c:46
int size
Definition: avcodec.h:909
AVCodec ff_aura2_decoder
Definition: aura.c:125
AVCodec.
Definition: avcodec.h:3189
Definition: vf_drawbox.c:32
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
#define av_cold
Definition: attributes.h:71
static av_cold int aura_decode_end(AVCodecContext *avctx)
Definition: aura.c:115
const char data[16]
Definition: mxf.c:60
uint8_t * data
Definition: avcodec.h:908
#define V
Definition: options.c:69
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:336
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:719
int reference
is this picture used as reference The values for this are the same as the MpegEncContext.picture_structure variable, that is 1->top field, 2->bottom field, 3->frame/both fields.
Definition: avcodec.h:1074
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
const char * name
Name of the codec implementation.
Definition: avcodec.h:3196
int width
picture width / height.
Definition: avcodec.h:1408
struct AVFrame AVFrame
Audio Video Frame.
external API header
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
main external API structure.
Definition: avcodec.h:1329
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:327
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
struct AuraDecodeContext AuraDecodeContext
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
void * priv_data
Definition: avcodec.h:1531
AVCodecContext * avctx
Definition: aura.c:29
Definition: vf_drawbox.c:32