FFmpeg
zerocodec.c
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1 /*
2  * ZeroCodec Decoder
3  *
4  * Copyright (c) 2012, Derek Buitenhuis
5  *
6  * Permission to use, copy, modify, and/or distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <zlib.h>
20 
21 #include "avcodec.h"
22 #include "codec_internal.h"
23 #include "decode.h"
24 #include "zlib_wrapper.h"
25 #include "libavutil/common.h"
26 
27 typedef struct ZeroCodecContext {
31 
33  int *got_frame, AVPacket *avpkt)
34 {
35  ZeroCodecContext *zc = avctx->priv_data;
36  AVFrame *prev_pic = zc->previous_frame;
37  z_stream *const zstream = &zc->zstream.zstream;
38  uint8_t *prev = prev_pic->data[0];
39  uint8_t *dst;
40  int i, j, zret, ret;
41 
42  if (avpkt->flags & AV_PKT_FLAG_KEY) {
43  pic->flags |= AV_FRAME_FLAG_KEY;
45  } else {
46  if (!prev) {
47  av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
48  return AVERROR_INVALIDDATA;
49  }
50 
51  prev += (avctx->height - 1) * prev_pic->linesize[0];
52 
53  pic->flags &= ~AV_FRAME_FLAG_KEY;
55  }
56 
57  zret = inflateReset(zstream);
58  if (zret != Z_OK) {
59  av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
60  return AVERROR_INVALIDDATA;
61  }
62 
63  if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
64  return ret;
65 
66  zstream->next_in = avpkt->data;
67  zstream->avail_in = avpkt->size;
68 
69  dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
70 
71  /**
72  * ZeroCodec has very simple interframe compression. If a value
73  * is the same as the previous frame, set it to 0.
74  */
75 
76  for (i = 0; i < avctx->height; i++) {
77  zstream->next_out = dst;
78  zstream->avail_out = avctx->width << 1;
79 
80  zret = inflate(zstream, Z_SYNC_FLUSH);
81  if (zret != Z_OK && zret != Z_STREAM_END) {
82  av_log(avctx, AV_LOG_ERROR,
83  "Inflate failed with return code: %d.\n", zret);
84  return AVERROR_INVALIDDATA;
85  }
86 
87  if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {
88  for (j = 0; j < avctx->width << 1; j++)
89  dst[j] += prev[j] & -!dst[j];
90  prev -= prev_pic->linesize[0];
91  }
92 
93  dst -= pic->linesize[0];
94  }
95 
96  if ((ret = av_frame_replace(zc->previous_frame, pic)) < 0)
97  return ret;
98 
99  *got_frame = 1;
100 
101  return avpkt->size;
102 }
103 
105 {
106  ZeroCodecContext *zc = avctx->priv_data;
107 
109 
110  ff_inflate_end(&zc->zstream);
111 
112  return 0;
113 }
114 
116 {
117  ZeroCodecContext *zc = avctx->priv_data;
118 
119  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
120  avctx->bits_per_raw_sample = 8;
121 
123  if (!zc->previous_frame)
124  return AVERROR(ENOMEM);
125 
126  return ff_inflate_init(&zc->zstream, avctx);
127 }
128 
130 {
131  ZeroCodecContext *zc = avctx->priv_data;
132 
134 }
135 
138  .p.name = "zerocodec",
139  CODEC_LONG_NAME("ZeroCodec Lossless Video"),
140  .p.id = AV_CODEC_ID_ZEROCODEC,
141  .priv_data_size = sizeof(ZeroCodecContext),
144  .flush = zerocodec_decode_flush,
145  .close = zerocodec_decode_close,
146  .p.capabilities = AV_CODEC_CAP_DR1,
147  .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
148 };
FF_CODEC_CAP_INIT_CLEANUP
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: codec_internal.h:42
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
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:100
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:374
FFCodec
Definition: codec_internal.h:127
FFZStream::zstream
z_stream zstream
Definition: zlib_wrapper.h:28
AVFrame::flags
int flags
Frame flags, a combination of AV_FRAME_FLAGS.
Definition: frame.h:649
zerocodec_decode_close
static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
Definition: zerocodec.c:104
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:429
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
zerocodec_decode_flush
static void zerocodec_decode_flush(AVCodecContext *avctx)
Definition: zerocodec.c:129
inflate
static void inflate(uint8_t *dst, const uint8_t *p1, int width, int threshold, const uint8_t *coordinates[], int coord, int maxc)
Definition: vf_neighbor.c:194
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:88
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
zlib_wrapper.h
av_cold
#define av_cold
Definition: attributes.h:90
AV_FRAME_FLAG_KEY
#define AV_FRAME_FLAG_KEY
A flag to mark frames that are keyframes.
Definition: frame.h:628
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:417
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts_bsf.c:365
AVCodecContext::bits_per_raw_sample
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:1513
decode.h
zerocodec_decode_frame
static int zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic, int *got_frame, AVPacket *avpkt)
Definition: zerocodec.c:32
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
zerocodec_decode_init
static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
Definition: zerocodec.c:115
AV_CODEC_ID_ZEROCODEC
@ AV_CODEC_ID_ZEROCODEC
Definition: codec_id.h:213
AVCodec::type
enum AVMediaType type
Definition: codec.h:200
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
ff_zerocodec_decoder
const FFCodec ff_zerocodec_decoder
Definition: zerocodec.c:136
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1575
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:442
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
codec_internal.h
for
for(k=2;k<=8;++k)
Definition: h264pred_template.c:425
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:380
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:270
ZeroCodecContext::zstream
FFZStream zstream
Definition: zerocodec.c:29
common.h
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:622
ff_inflate_end
void ff_inflate_end(FFZStream *zstream)
Wrapper around inflateEnd().
AVCodecContext::height
int height
Definition: avcodec.h:617
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:654
avcodec.h
ret
ret
Definition: filter_design.txt:187
AV_PIX_FMT_UYVY422
@ AV_PIX_FMT_UYVY422
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:81
ZeroCodecContext
Definition: zerocodec.c:27
av_frame_replace
int av_frame_replace(AVFrame *dst, const AVFrame *src)
Ensure the destination frame refers to the same data described by the source frame,...
Definition: frame.c:482
AVCodecContext
main external API structure.
Definition: avcodec.h:437
ZeroCodecContext::previous_frame
AVFrame * previous_frame
Definition: zerocodec.c:28
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
FFZStream
Definition: zlib_wrapper.h:27
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:464
AVPacket
This structure stores compressed data.
Definition: packet.h:351
ff_inflate_init
int ff_inflate_init(FFZStream *zstream, void *logctx)
Wrapper around inflateInit().
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:617
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:385
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