Libav
vcr1.c
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1 /*
2  * ATI VCR1 codec
3  * Copyright (c) 2003 Michael Niedermayer
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "libavutil/internal.h"
30 
31 typedef struct VCR1Context {
32  int delta[16];
33  int offset[4];
34 } VCR1Context;
35 
37 {
38  avctx->pix_fmt = AV_PIX_FMT_YUV410P;
39 
40  if (avctx->width & 7) {
41  av_log(avctx, AV_LOG_ERROR, "Width %d is not divisble by 8.\n", avctx->width);
42  return AVERROR_INVALIDDATA;
43  }
44 
45  return 0;
46 }
47 
48 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
49  int *got_frame, AVPacket *avpkt)
50 {
51  const uint8_t *buf = avpkt->data;
52  int buf_size = avpkt->size;
53  VCR1Context *const a = avctx->priv_data;
54  AVFrame *const p = data;
55  const uint8_t *bytestream = buf;
56  int i, x, y, ret;
57 
58  if ((ret = ff_get_buffer(avctx, p, 0)) < 0) {
59  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
60  return ret;
61  }
63  p->key_frame = 1;
64 
65  if (buf_size < 32)
66  goto packet_small;
67 
68  for (i = 0; i < 16; i++) {
69  a->delta[i] = *bytestream++;
70  bytestream++;
71  buf_size--;
72  }
73 
74  for (y = 0; y < avctx->height; y++) {
75  int offset;
76  uint8_t *luma = &p->data[0][y * p->linesize[0]];
77 
78  if ((y & 3) == 0) {
79  uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
80  uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
81 
82  if (buf_size < 4 + avctx->width)
83  goto packet_small;
84 
85  for (i = 0; i < 4; i++)
86  a->offset[i] = *bytestream++;
87  buf_size -= 4;
88 
89  offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
90  for (x = 0; x < avctx->width; x += 4) {
91  luma[0] = offset += a->delta[bytestream[2] & 0xF];
92  luma[1] = offset += a->delta[bytestream[2] >> 4];
93  luma[2] = offset += a->delta[bytestream[0] & 0xF];
94  luma[3] = offset += a->delta[bytestream[0] >> 4];
95  luma += 4;
96 
97  *cb++ = bytestream[3];
98  *cr++ = bytestream[1];
99 
100  bytestream += 4;
101  buf_size -= 4;
102  }
103  } else {
104  if (buf_size < avctx->width / 2)
105  goto packet_small;
106 
107  offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
108 
109  for (x = 0; x < avctx->width; x += 8) {
110  luma[0] = offset += a->delta[bytestream[2] & 0xF];
111  luma[1] = offset += a->delta[bytestream[2] >> 4];
112  luma[2] = offset += a->delta[bytestream[3] & 0xF];
113  luma[3] = offset += a->delta[bytestream[3] >> 4];
114  luma[4] = offset += a->delta[bytestream[0] & 0xF];
115  luma[5] = offset += a->delta[bytestream[0] >> 4];
116  luma[6] = offset += a->delta[bytestream[1] & 0xF];
117  luma[7] = offset += a->delta[bytestream[1] >> 4];
118  luma += 8;
119  bytestream += 4;
120  buf_size -= 4;
121  }
122  }
123  }
124 
125  *got_frame = 1;
126 
127  return buf_size;
128 packet_small:
129  av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n");
130  return AVERROR_INVALIDDATA;
131 }
132 
134  .name = "vcr1",
135  .long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
136  .type = AVMEDIA_TYPE_VIDEO,
137  .id = AV_CODEC_ID_VCR1,
138  .priv_data_size = sizeof(VCR1Context),
141  .capabilities = CODEC_CAP_DR1,
142 };
#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:107
int size
Definition: avcodec.h:974
static av_cold int vcr1_decode_init(AVCodecContext *avctx)
Definition: vcr1.c:36
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1247
AVCodec.
Definition: avcodec.h:2755
int offset[4]
Definition: vcr1.c:33
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:269
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:711
const char data[16]
Definition: mxf.c:66
uint8_t * data
Definition: avcodec.h:973
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:142
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
const char * name
Name of the codec implementation.
Definition: avcodec.h:2762
common internal API header
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:168
int width
picture width / height.
Definition: avcodec.h:1217
int delta[16]
Definition: vcr1.c:32
static int width
Definition: utils.c:156
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:125
main external API structure.
Definition: avcodec.h:1054
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:575
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:71
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:113
AVCodec ff_vcr1_decoder
Definition: vcr1.c:133
common internal api header.
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:498
static int vcr1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: vcr1.c:48
void * priv_data
Definition: avcodec.h:1090
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:163
This structure stores compressed data.
Definition: avcodec.h:950
for(j=16;j >0;--j)