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 
30 typedef struct AuraDecodeContext {
34 
36 {
37  AuraDecodeContext *s = avctx->priv_data;
38 
39  s->avctx = avctx;
40  /* width needs to be divisible by 4 for this codec to work */
41  if (avctx->width & 0x3)
42  return -1;
43  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
44 
45  return 0;
46 }
47 
49  void *data, int *got_frame,
50  AVPacket *pkt)
51 {
52  AuraDecodeContext *s = avctx->priv_data;
53  uint8_t *Y, *U, *V;
54  uint8_t val;
55  int x, y;
56  const uint8_t *buf = pkt->data;
57 
58  /* prediction error tables (make it clear that they are signed values) */
59  const int8_t *delta_table = (const int8_t*)buf + 16;
60 
61  if (pkt->size != 48 + avctx->height * avctx->width) {
62  av_log(avctx, AV_LOG_ERROR, "got a buffer with %d bytes when %d were expected\n",
63  pkt->size, 48 + avctx->height * avctx->width);
64  return -1;
65  }
66 
67  /* pixel data starts 48 bytes in, after 3x16-byte tables */
68  buf += 48;
69 
70  if (s->frame.data[0])
71  avctx->release_buffer(avctx, &s->frame);
72 
74  s->frame.reference = 0;
75  if (ff_get_buffer(avctx, &s->frame) < 0) {
76  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
77  return -1;
78  }
79 
80  Y = s->frame.data[0];
81  U = s->frame.data[1];
82  V = s->frame.data[2];
83 
84  /* iterate through each line in the height */
85  for (y = 0; y < avctx->height; y++) {
86  /* reset predictors */
87  val = *buf++;
88  U[0] = val & 0xF0;
89  Y[0] = val << 4;
90  val = *buf++;
91  V[0] = val & 0xF0;
92  Y[1] = Y[0] + delta_table[val & 0xF];
93  Y += 2; U++; V++;
94 
95  /* iterate through the remaining pixel groups (4 pixels/group) */
96  for (x = 1; x < (avctx->width >> 1); x++) {
97  val = *buf++;
98  U[0] = U[-1] + delta_table[val >> 4];
99  Y[0] = Y[-1] + delta_table[val & 0xF];
100  val = *buf++;
101  V[0] = V[-1] + delta_table[val >> 4];
102  Y[1] = Y[ 0] + delta_table[val & 0xF];
103  Y += 2; U++; V++;
104  }
105  Y += s->frame.linesize[0] - avctx->width;
106  U += s->frame.linesize[1] - (avctx->width >> 1);
107  V += s->frame.linesize[2] - (avctx->width >> 1);
108  }
109 
110  *got_frame = 1;
111  *(AVFrame*)data = s->frame;
112 
113  return pkt->size;
114 }
115 
117 {
118  AuraDecodeContext *s = avctx->priv_data;
119 
120  if (s->frame.data[0])
121  avctx->release_buffer(avctx, &s->frame);
122 
123  return 0;
124 }
125 
127  .name = "aura2",
128  .type = AVMEDIA_TYPE_VIDEO,
129  .id = AV_CODEC_ID_AURA2,
130  .priv_data_size = sizeof(AuraDecodeContext),
134  .capabilities = CODEC_CAP_DR1,
135  .long_name = NULL_IF_CONFIG_SMALL("Auravision Aura 2"),
136 };
AVFrame frame
Definition: aura.c:32
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
static av_cold int aura_decode_init(AVCodecContext *avctx)
Definition: aura.c:35
int buffer_hints
codec suggestion on buffer type if != 0
Definition: avcodec.h:1253
void(* release_buffer)(struct AVCodecContext *c, AVFrame *pic)
Called to release buffers which were allocated with get_buffer.
Definition: avcodec.h:2259
int size
Definition: avcodec.h:916
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1533
AVCodec ff_aura2_decoder
Definition: aura.c:126
AVCodec.
Definition: avcodec.h:2960
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
uint8_t
static av_cold int aura_decode_end(AVCodecContext *avctx)
Definition: aura.c:116
const char data[16]
Definition: mxf.c:66
uint8_t * data
Definition: avcodec.h:915
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:335
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:1132
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:88
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
const char * name
Name of the codec implementation.
Definition: avcodec.h:2967
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:69
Definition: vf_drawbox.c:36
common internal API header
int width
picture width / height.
Definition: avcodec.h:1508
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame)
Get a buffer for a frame.
Definition: utils.c:464
external API header
int linesize[AV_NUM_DATA_POINTERS]
Size, in bytes, of the data for each picture/channel plane.
Definition: avcodec.h:1008
static int aura_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *pkt)
Definition: aura.c:48
main external API structure.
Definition: avcodec.h:1339
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:326
struct AuraDecodeContext AuraDecodeContext
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
Definition: vf_drawbox.c:36
common internal api header.
void * priv_data
Definition: avcodec.h:1382
AVCodecContext * avctx
Definition: aura.c:31
This structure stores compressed data.
Definition: avcodec.h:898