vcr1.c
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1 /*
2  * ATI VCR1 codec
3  * Copyright (c) 2003 Michael Niedermayer
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * ATI VCR1 codec
25  */
26 
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 % 8 || avctx->height%4) {
41  avpriv_request_sample(avctx, "odd dimensions support");
42  return AVERROR_PATCHWELCOME;
43  }
44  return 0;
45 }
46 
47 static int vcr1_decode_frame(AVCodecContext *avctx, void *data,
48  int *got_frame, AVPacket *avpkt)
49 {
50  const uint8_t *buf = avpkt->data;
51  int buf_size = avpkt->size;
52  VCR1Context *const a = avctx->priv_data;
53  AVFrame *const p = data;
54  const uint8_t *bytestream = buf;
55  int i, x, y, ret;
56 
57  if(buf_size < 16 + avctx->height + avctx->width*avctx->height*5/8){
58  av_log(avctx, AV_LOG_ERROR, "Insufficient input data.\n");
59  return AVERROR(EINVAL);
60  }
61 
62  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
63  return ret;
65  p->key_frame = 1;
66 
67  for (i = 0; i < 16; i++) {
68  a->delta[i] = *bytestream++;
69  bytestream++;
70  }
71 
72  for (y = 0; y < avctx->height; y++) {
73  int offset;
74  uint8_t *luma = &p->data[0][y * p->linesize[0]];
75 
76  if ((y & 3) == 0) {
77  uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]];
78  uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]];
79 
80  for (i = 0; i < 4; i++)
81  a->offset[i] = *bytestream++;
82 
83  offset = a->offset[0] - a->delta[bytestream[2] & 0xF];
84  for (x = 0; x < avctx->width; x += 4) {
85  luma[0] = offset += a->delta[bytestream[2] & 0xF];
86  luma[1] = offset += a->delta[bytestream[2] >> 4];
87  luma[2] = offset += a->delta[bytestream[0] & 0xF];
88  luma[3] = offset += a->delta[bytestream[0] >> 4];
89  luma += 4;
90 
91  *cb++ = bytestream[3];
92  *cr++ = bytestream[1];
93 
94  bytestream += 4;
95  }
96  } else {
97  offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF];
98 
99  for (x = 0; x < avctx->width; x += 8) {
100  luma[0] = offset += a->delta[bytestream[2] & 0xF];
101  luma[1] = offset += a->delta[bytestream[2] >> 4];
102  luma[2] = offset += a->delta[bytestream[3] & 0xF];
103  luma[3] = offset += a->delta[bytestream[3] >> 4];
104  luma[4] = offset += a->delta[bytestream[0] & 0xF];
105  luma[5] = offset += a->delta[bytestream[0] >> 4];
106  luma[6] = offset += a->delta[bytestream[1] & 0xF];
107  luma[7] = offset += a->delta[bytestream[1] >> 4];
108  luma += 8;
109  bytestream += 4;
110  }
111  }
112  }
113 
114  *got_frame = 1;
115 
116  return buf_size;
117 }
118 
120  .name = "vcr1",
121  .type = AVMEDIA_TYPE_VIDEO,
122  .id = AV_CODEC_ID_VCR1,
123  .priv_data_size = sizeof(VCR1Context),
126  .capabilities = CODEC_CAP_DR1,
127  .long_name = NULL_IF_CONFIG_SMALL("ATI VCR1"),
128 };
Definition: frame.h:76
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static av_cold int vcr1_decode_init(AVCodecContext *avctx)
Definition: vcr1.c:36
enum AVPixelFormat pix_fmt
int offset[4]
Definition: vcr1.c:33
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
uint8_t
#define av_cold
Definition: attributes.h:78
#define CODEC_CAP_DR1
uint8_t * data
Discrete Time axis x
#define NULL_IF_CONFIG_SMALL(x)
Spectrum Plot time data
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:246
const char * name
struct VCR1Context VCR1Context
enum AVPictureType pict_type
Definition: frame.h:144
ret
Definition: avfilter.c:821
int delta[16]
Definition: vcr1.c:32
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
int linesize[AV_NUM_DATA_POINTERS]
Definition: frame.h:101
FIXME Range Coding of cb
Definition: snow.txt:367
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
#define AV_LOG_ERROR
Definition: log.h:148
void * buf
Definition: avisynth_c.h:594
BYTE int const BYTE int int int height
Definition: avisynth_c.h:713
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:74
synthesis window for stochastic i
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Buffer references ownership and permissions
uint8_t * data[AV_NUM_DATA_POINTERS]
Definition: frame.h:87
AVCodec ff_vcr1_decoder
Definition: vcr1.c:119
function y
Definition: D.m:1
static int vcr1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: vcr1.c:47
int key_frame
Definition: frame.h:139
static int decode(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: crystalhd.c:868
static double cr(void *priv, double x, double y)
Definition: vf_geq.c:85
for(j=16;j >0;--j)