Libav
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 {
27  z_stream zstream;
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;
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;
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 (ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF) < 0) {
63  av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
64  return AVERROR(ENOMEM);
65  }
66 
67  zstream->next_in = avpkt->data;
68  zstream->avail_in = avpkt->size;
69 
70  dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
71 
77  for (i = 0; i < avctx->height; i++) {
78  zstream->next_out = dst;
79  zstream->avail_out = avctx->width << 1;
80 
81  zret = inflate(zstream, Z_SYNC_FLUSH);
82  if (zret != Z_OK && zret != Z_STREAM_END) {
83  av_log(avctx, AV_LOG_ERROR,
84  "Inflate failed with return code: %d.\n", zret);
85  return AVERROR_INVALIDDATA;
86  }
87 
88  if (!(avpkt->flags & AV_PKT_FLAG_KEY))
89  for (j = 0; j < avctx->width << 1; j++)
90  dst[j] += prev[j] & -!dst[j];
91 
92  prev -= prev_pic->linesize[0];
93  dst -= pic->linesize[0];
94  }
95 
97  if ((ret = av_frame_ref(zc->previous_frame, pic)) < 0)
98  return ret;
99 
100  *got_frame = 1;
101 
102  return avpkt->size;
103 }
104 
106 {
107  ZeroCodecContext *zc = avctx->priv_data;
108 
110 
111  inflateEnd(&zc->zstream);
112 
113  return 0;
114 }
115 
117 {
118  ZeroCodecContext *zc = avctx->priv_data;
119  z_stream *zstream = &zc->zstream;
120  int zret;
121 
122  avctx->pix_fmt = AV_PIX_FMT_UYVY422;
123  avctx->bits_per_raw_sample = 8;
124 
125  zstream->zalloc = Z_NULL;
126  zstream->zfree = Z_NULL;
127  zstream->opaque = Z_NULL;
128 
129  zret = inflateInit(zstream);
130  if (zret != Z_OK) {
131  av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
132  return AVERROR(ENOMEM);
133  }
134 
136  if (!zc->previous_frame) {
137  zerocodec_decode_close(avctx);
138  return AVERROR(ENOMEM);
139  }
140 
141  return 0;
142 }
143 
146  .name = "zerocodec",
147  .long_name = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
148  .id = AV_CODEC_ID_ZEROCODEC,
149  .priv_data_size = sizeof(ZeroCodecContext),
153  .capabilities = CODEC_CAP_DR1,
154 };