FFmpeg: libavcodec/zerocodec.c Source File

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 "internal.h"
23 #include "libavutil/common.h"
24 
25  typedef struct ZeroCodecContext {
26   AVFrame *previous_frame;
27   z_stream zstream;
28 } ZeroCodecContext;
29 
30  static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
31  int *got_frame, AVPacket *avpkt)
32 {
33  ZeroCodecContext *zc = avctx->priv_data;
34  AVFrame *pic = data;
35  AVFrame *prev_pic = zc->previous_frame;
36  z_stream *zstream = &zc->zstream;
37  uint8_t *prev = prev_pic->data[0];
38  uint8_t *dst;
39  int i, j, zret, ret;
40 
41  if (avpkt->flags & AV_PKT_FLAG_KEY) {
42  pic->key_frame = 1;
43  pic->pict_type = AV_PICTURE_TYPE_I;
44  } else {
45  if (!prev) {
46  av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
47  return AVERROR_INVALIDDATA;
48  }
49 
50  prev += (avctx->height - 1) * prev_pic->linesize[0];
51 
52  pic->key_frame = 0;
53  pic->pict_type = AV_PICTURE_TYPE_P;
54  }
55 
56  zret = inflateReset(zstream);
57  if (zret != Z_OK) {
58  av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
59  return AVERROR_INVALIDDATA;
60  }
61 
62  if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
63  return ret;
64 
65  zstream->next_in = avpkt->data;
66  zstream->avail_in = avpkt->size;
67 
68  dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
69 
70  /**
71  * ZeroCodec has very simple interframe compression. If a value
72  * is the same as the previous frame, set it to 0.
73  */
74 
75  for (i = 0; i < avctx->height; i++) {
76  zstream->next_out = dst;
77  zstream->avail_out = avctx->width << 1;
78 
79  zret = inflate(zstream, Z_SYNC_FLUSH);
80  if (zret != Z_OK && zret != Z_STREAM_END) {
81  av_log(avctx, AV_LOG_ERROR,
82  "Inflate failed with return code: %d.\n", zret);
83  return AVERROR_INVALIDDATA;
84  }
85 
86  if (!(avpkt->flags & AV_PKT_FLAG_KEY))
87  for (j = 0; j < avctx->width << 1; j++)
88  dst[j] += prev[j] & -!dst[j];
89 
90  prev -= prev_pic->linesize[0];
91  dst -= pic->linesize[0];
92  }
93 
94  av_frame_unref(zc->previous_frame);
95  if ((ret = av_frame_ref(zc->previous_frame, pic)) < 0)
96  return ret;
97 
98  *got_frame = 1;
99 
100  return avpkt->size;
101 }
102 
103  static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
104 {
105  ZeroCodecContext *zc = avctx->priv_data;
106 
107  av_frame_free(&zc->previous_frame);
108 
109  inflateEnd(&zc->zstream);
110 
111  return 0;
112 }
113 
114  static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
115 {
116  ZeroCodecContext *zc = avctx->priv_data;
117  z_stream *zstream = &zc->zstream;
118  int zret;
119 
120  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
121  avctx->bits_per_raw_sample = 8;
122 
123  zstream->zalloc = Z_NULL;
124  zstream->zfree = Z_NULL;
125  zstream->opaque = Z_NULL;
126 
127  zret = inflateInit(zstream);
128  if (zret != Z_OK) {
129  av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
130  return AVERROR(ENOMEM);
131  }
132 
133  zc->previous_frame = av_frame_alloc();
134  if (!zc->previous_frame) {
135  zerocodec_decode_close(avctx);
136  return AVERROR(ENOMEM);
137  }
138 
139  return 0;
140 }
141 
142  AVCodec ff_zerocodec_decoder = {
143  .type = AVMEDIA_TYPE_VIDEO,
144  .name = "zerocodec",
145  .long_name = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
146  .id = AV_CODEC_ID_ZEROCODEC,
147  .priv_data_size = sizeof(ZeroCodecContext),
148  .init = zerocodec_decode_init,
149  .decode = zerocodec_decode_frame,
150  .close = zerocodec_decode_close,
151  .capabilities = AV_CODEC_CAP_DR1,
152  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
153 };
AV_PIX_FMT_UYVY422
packed YUV 4:2:2, 16bpp, Cb Y0 Cr Y1
Definition: pixfmt.h:77
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:218
data
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
AVPacket::size
int size
Definition: avcodec.h:1431
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1727
ZeroCodecContext::zstream
z_stream zstream
Definition: zerocodec.c:27
AVCodec::type
enum AVMediaType type
Definition: avcodec.h:3421
AVCodecContext::bits_per_raw_sample
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:2741
AVCodec
AVCodec.
Definition: avcodec.h:3408
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
FF_CODEC_CAP_INIT_THREADSAFE
#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:40
uint8_t
uint8_t
Definition: audio_convert.c:194
av_cold
#define av_cold
Definition: attributes.h:82
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
av_frame_ref
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:441
zerocodec_decode_close
static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
Definition: zerocodec.c:103
AVPacket::data
uint8_t * data
Definition: avcodec.h:1430
inflate
static void inflate(uint8_t *dst, const uint8_t *p1, int width, int threshold, const uint8_t *coordinates[], int coord)
Definition: vf_neighbor.c:129
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
zerocodec_decode_frame
static int zerocodec_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: zerocodec.c:30
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1462
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVERROR
#define AVERROR(e)
Definition: error.h:43
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
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:186
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1436
AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
AVFrame::pict_type
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:301
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:1690
AVCodecContext::height
int height
Definition: avcodec.h:1690
avcodec.h
Libavcodec external API header.
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:249
AVCodecContext
main external API structure.
Definition: avcodec.h:1518
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1891
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:551
ZeroCodecContext::previous_frame
AVFrame * previous_frame
Definition: zerocodec.c:26
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:232
internal.h
common internal api header.
common.h
common internal and external API header
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:1545
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:296
zerocodec_decode_init
static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
Definition: zerocodec.c:114
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1407
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:1135
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:959
for
for(j=16;j >0;--j)
Definition: h264pred_template.c:469
ff_zerocodec_decoder
AVCodec ff_zerocodec_decoder
Definition: zerocodec.c:142
AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275

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