FFmpeg
frwu.c
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1 /*
2  * Forward Uncompressed
3  *
4  * Copyright (c) 2009 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "avcodec.h"
24 #include "bytestream.h"
25 #include "codec_internal.h"
26 #include "internal.h"
27 #include "libavutil/opt.h"
28 
29 typedef struct {
32 } FRWUContext;
33 
35 {
36  if (avctx->width & 1) {
37  av_log(avctx, AV_LOG_ERROR, "frwu needs even width\n");
38  return AVERROR(EINVAL);
39  }
40  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
41 
42  return 0;
43 }
44 
45 static int decode_frame(AVCodecContext *avctx, AVFrame *pic,
46  int *got_frame, AVPacket *avpkt)
47 {
48  FRWUContext *s = avctx->priv_data;
49  int field, ret;
50  const uint8_t *buf = avpkt->data;
51  const uint8_t *buf_end = buf + avpkt->size;
52 
53  if (avpkt->size < avctx->width * 2 * avctx->height + 4 + 2*8) {
54  av_log(avctx, AV_LOG_ERROR, "Packet is too small.\n");
55  return AVERROR_INVALIDDATA;
56  }
57  if (bytestream_get_le32(&buf) != MKTAG('F', 'R', 'W', '1')) {
58  av_log(avctx, AV_LOG_ERROR, "incorrect marker\n");
59  return AVERROR_INVALIDDATA;
60  }
61 
62  if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
63  return ret;
64 
66  pic->key_frame = 1;
67 
68  for (field = 0; field < 2; field++) {
69  int i;
70  int field_h = (avctx->height + !field) >> 1;
71  int field_size, min_field_size = avctx->width * 2 * field_h;
72  uint8_t *dst = pic->data[0];
73  if (buf_end - buf < 8)
74  return AVERROR_INVALIDDATA;
75  buf += 4; // flags? 0x80 == bottom field maybe?
76  field_size = bytestream_get_le32(&buf);
77  if (field_size < min_field_size) {
78  av_log(avctx, AV_LOG_ERROR, "Field size %i is too small (required %i)\n", field_size, min_field_size);
79  return AVERROR_INVALIDDATA;
80  }
81  if (buf_end - buf < field_size) {
82  av_log(avctx, AV_LOG_ERROR, "Packet is too small, need %i, have %i\n", field_size, (int)(buf_end - buf));
83  return AVERROR_INVALIDDATA;
84  }
85  if (field ^ s->change_field_order) {
86  dst += pic->linesize[0];
87  } else if (s->change_field_order) {
88  dst += 2 * pic->linesize[0];
89  }
90  for (i = 0; i < field_h; i++) {
91  if (s->change_field_order && field && i == field_h - 1)
92  dst = pic->data[0];
93  memcpy(dst, buf, avctx->width * 2);
94  buf += avctx->width * 2;
95  dst += pic->linesize[0] << 1;
96  }
97  buf += field_size - min_field_size;
98  }
99 
100  *got_frame = 1;
101 
102  return avpkt->size;
103 }
104 
105 static const AVOption frwu_options[] = {
106  {"change_field_order", "Change field order", offsetof(FRWUContext, change_field_order), AV_OPT_TYPE_BOOL,
108  {NULL}
109 };
110 
111 static const AVClass frwu_class = {
112  .class_name = "frwu Decoder",
113  .item_name = av_default_item_name,
114  .option = frwu_options,
115  .version = LIBAVUTIL_VERSION_INT,
116 };
117 
119  .p.name = "frwu",
120  .p.long_name = NULL_IF_CONFIG_SMALL("Forward Uncompressed"),
121  .p.type = AVMEDIA_TYPE_VIDEO,
122  .p.id = AV_CODEC_ID_FRWU,
123  .priv_data_size = sizeof(FRWUContext),
124  .init = decode_init,
126  .p.capabilities = AV_CODEC_CAP_DR1,
127  .p.priv_class = &frwu_class,
128 };
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame 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. Frame references ownership and permissions
opt.h
AV_OPT_FLAG_VIDEO_PARAM
#define AV_OPT_FLAG_VIDEO_PARAM
Definition: opt.h:284
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
FFCodec
Definition: codec_internal.h:118
FRWUContext
Definition: frwu.c:29
decode_frame
static int decode_frame(AVCodecContext *avctx, AVFrame *pic, int *got_frame, AVPacket *avpkt)
Definition: frwu.c:45
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
init
static int init
Definition: av_tx.c:47
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:122
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:417
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:260
s
#define s(width, name)
Definition: cbs_vp9.c:256
ff_frwu_decoder
const FFCodec ff_frwu_decoder
Definition: frwu.c:118
field
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this field
Definition: writing_filters.txt:78
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:422
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1462
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:375
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
codec_internal.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AV_CODEC_ID_FRWU
@ AV_CODEC_ID_FRWU
Definition: codec_id.h:180
AV_OPT_FLAG_DECODING_PARAM
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:282
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:211
AVCodecContext::height
int height
Definition: avcodec.h:571
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:608
FRWUContext::change_field_order
int change_field_order
Definition: frwu.c:31
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
frwu_class
static const AVClass frwu_class
Definition: frwu.c:111
AV_PIX_FMT_UYVY422
@ AV_PIX_FMT_UYVY422
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:81
FRWUContext::av_class
AVClass * av_class
Definition: frwu.c:30
AVCodecContext
main external API structure.
Definition: avcodec.h:398
frwu_options
static const AVOption frwu_options[]
Definition: frwu.c:105
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: frwu.c:34
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:244
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:571
bytestream.h
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:370
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55