FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/zerocodec.c
Date: 2025-10-25 08:50:29
Exec Total Coverage
Lines: 43 56 76.8%
Functions: 3 4 75.0%
Branches: 16 22 72.7%
Line Branch Exec Source
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/attributes.h"
26 #include "libavutil/common.h"
27
28 typedef struct ZeroCodecContext {
29 AVFrame *previous_frame;
30 FFZStream zstream;
31 } ZeroCodecContext;
32
33 38 static int zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic,
34 int *got_frame, AVPacket *avpkt)
35 {
36 38 ZeroCodecContext *zc = avctx->priv_data;
37 38 AVFrame *prev_pic = zc->previous_frame;
38 38 z_stream *const zstream = &zc->zstream.zstream;
39 38 uint8_t *prev = prev_pic->data[0];
40 uint8_t *dst;
41 int i, j, zret, ret;
42
43
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 38 if (avpkt->flags & AV_PKT_FLAG_KEY) {
44 3 pic->flags |= AV_FRAME_FLAG_KEY;
45 3 pic->pict_type = AV_PICTURE_TYPE_I;
46 } else {
47
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 35 if (!prev) {
48 ✗ av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
49 ✗ return AVERROR_INVALIDDATA;
50 }
51
52 35 prev += (avctx->height - 1) * prev_pic->linesize[0];
53
54 35 pic->flags &= ~AV_FRAME_FLAG_KEY;
55 35 pic->pict_type = AV_PICTURE_TYPE_P;
56 }
57
58 38 zret = inflateReset(zstream);
59
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 38 if (zret != Z_OK) {
60 ✗ av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
61 ✗ return AVERROR_INVALIDDATA;
62 }
63
64
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 38 if ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
65 ✗ return ret;
66
67 38 zstream->next_in = avpkt->data;
68 38 zstream->avail_in = avpkt->size;
69
70 38 dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
71
72 /**
73 * ZeroCodec has very simple interframe compression. If a value
74 * is the same as the previous frame, set it to 0.
75 */
76
77
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 27398 for (i = 0; i < avctx->height; i++) {
78 27360 zstream->next_out = dst;
79 27360 zstream->avail_out = avctx->width << 1;
80
81 27360 zret = inflate(zstream, Z_SYNC_FLUSH);
82
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 27360 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
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 27360 if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {
89
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 64537200 for (j = 0; j < avctx->width << 1; j++)
90 64512000 dst[j] += prev[j] & -!dst[j];
91 25200 prev -= prev_pic->linesize[0];
92 }
93
94 27360 dst -= pic->linesize[0];
95 }
96
97
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 38 if ((ret = av_frame_replace(zc->previous_frame, pic)) < 0)
98 ✗ return ret;
99
100 38 *got_frame = 1;
101
102 38 return avpkt->size;
103 }
104
105 2 static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
106 {
107 2 ZeroCodecContext *zc = avctx->priv_data;
108
109 2 av_frame_free(&zc->previous_frame);
110
111 2 ff_inflate_end(&zc->zstream);
112
113 2 return 0;
114 }
115
116 2 static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
117 {
118 2 ZeroCodecContext *zc = avctx->priv_data;
119
120 2 avctx->pix_fmt = AV_PIX_FMT_UYVY422;
121 2 avctx->bits_per_raw_sample = 8;
122
123 2 zc->previous_frame = av_frame_alloc();
124
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 2 if (!zc->previous_frame)
125 ✗ return AVERROR(ENOMEM);
126
127 2 return ff_inflate_init(&zc->zstream, avctx);
128 }
129
130 ✗ static av_cold void zerocodec_decode_flush(AVCodecContext *avctx)
131 {
132 ✗ ZeroCodecContext *zc = avctx->priv_data;
133
134 ✗ av_frame_unref(zc->previous_frame);
135 ✗ }
136
137 const FFCodec ff_zerocodec_decoder = {
138 .p.type = AVMEDIA_TYPE_VIDEO,
139 .p.name = "zerocodec",
140 CODEC_LONG_NAME("ZeroCodec Lossless Video"),
141 .p.id = AV_CODEC_ID_ZEROCODEC,
142 .priv_data_size = sizeof(ZeroCodecContext),
143 .init = zerocodec_decode_init,
144 FF_CODEC_DECODE_CB(zerocodec_decode_frame),
145 .flush = zerocodec_decode_flush,
146 .close = zerocodec_decode_close,
147 .p.capabilities = AV_CODEC_CAP_DR1,
148 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
149 };
150