FFmpeg
avrndec.c
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1 /*
2  * AVRn decoder
3  * Copyright (c) 2012 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 #include "avcodec.h"
23 #include "internal.h"
24 #include "libavutil/imgutils.h"
25 
26 typedef struct {
27  int interlace;
28  int tff;
29 } AVRnContext;
30 
31 static av_cold int init(AVCodecContext *avctx)
32 {
33  AVRnContext *a = avctx->priv_data;
34  int ret;
35 
36  if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)
37  return ret;
38 
39  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
40 
41  if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {
42  int ndx = avctx->extradata[4] + 4;
43  a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);
44  if(a->interlace) {
45  a->tff = avctx->extradata[ndx + 24] == 1;
46  }
47  }
48 
49  return 0;
50 }
51 
52 static int decode_frame(AVCodecContext *avctx, void *data,
53  int *got_frame, AVPacket *avpkt)
54 {
55  AVRnContext *a = avctx->priv_data;
56  AVFrame *p = data;
57  const uint8_t *buf = avpkt->data;
58  int buf_size = avpkt->size;
59  int y, ret, true_height;
60 
61  true_height = buf_size / (2*avctx->width);
62 
63  if(buf_size < 2*avctx->width * avctx->height) {
64  av_log(avctx, AV_LOG_ERROR, "packet too small\n");
65  return AVERROR_INVALIDDATA;
66  }
67 
68  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
69  return ret;
71  p->key_frame= 1;
72 
73  if(a->interlace) {
74  buf += (true_height - avctx->height)*avctx->width;
75  for(y = 0; y < avctx->height-1; y+=2) {
76  memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf , 2*avctx->width);
77  memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);
78  buf += 2*avctx->width;
79  }
80  } else {
81  buf += (true_height - avctx->height)*avctx->width*2;
82  for(y = 0; y < avctx->height; y++) {
83  memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);
84  buf += 2*avctx->width;
85  }
86  }
87 
88  *got_frame = 1;
89  return buf_size;
90 }
91 
93  .name = "avrn",
94  .long_name = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),
95  .type = AVMEDIA_TYPE_VIDEO,
96  .id = AV_CODEC_ID_AVRN,
97  .priv_data_size = sizeof(AVRnContext),
98  .init = init,
100  .capabilities = AV_CODEC_CAP_DR1,
102 };
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: internal.h:49
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:81
AVCodec ff_avrn_decoder
Definition: avrndec.c:92
#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:318
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: avrndec.c:52
misc image utilities
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
int size
Definition: packet.h:370
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:36
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:746
AVCodec.
Definition: codec.h:197
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
uint8_t
#define av_cold
Definition: attributes.h:88
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:637
#define height
uint8_t * data
Definition: packet.h:369
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:117
const char * name
Name of the codec implementation.
Definition: codec.h:204
int interlace
Definition: avrndec.c:27
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:317
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:401
#define width
int width
picture width / height.
Definition: avcodec.h:709
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
main external API structure.
Definition: avcodec.h:536
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1893
int extradata_size
Definition: avcodec.h:638
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
common internal api header.
void * priv_data
Definition: avcodec.h:563
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:396
int tff
Definition: avrndec.c:28
This structure stores compressed data.
Definition: packet.h:346
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators...
Definition: codec.h:52