summaryrefslogtreecommitdiff
path: root/libavcodec/zerocodec.c
blob: c8c2453a56753d946b41c1e0ac0ad6d4d9097410 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/*
 * ZeroCodec Decoder
 *
 * Copyright (c) 2012, Derek Buitenhuis
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <zlib.h>

#include "avcodec.h"

typedef struct {
    AVFrame  previous_frame;
    z_stream zstream;
    int      size;
} ZeroCodecContext;

static int zerocodec_decode_frame(AVCodecContext *avctx, void *data,
                                  int *data_size, AVPacket *avpkt)
{
    ZeroCodecContext *zc = avctx->priv_data;
    AVFrame *pic         = avctx->coded_frame;
    AVFrame *prev_pic    = &zc->previous_frame;
    z_stream *zstream    = &zc->zstream;
    uint8_t *prev        = prev_pic->data[0];
    uint8_t *dst;
    int i, j, zret;

    pic->reference = 3;

    if (avpkt->flags & AV_PKT_FLAG_KEY) {
        pic->key_frame = 1;
        pic->pict_type = AV_PICTURE_TYPE_I;
    } else {
        if (!prev) {
            av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
            return AVERROR_INVALIDDATA;
        }
        pic->key_frame = 0;
        pic->pict_type = AV_PICTURE_TYPE_P;
    }

    zret = inflateReset(zstream);
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
        return AVERROR_INVALIDDATA;
    }

    if (avctx->get_buffer(avctx, pic) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
        return AVERROR(ENOMEM);
    }

    zstream->next_in  = avpkt->data;
    zstream->avail_in = avpkt->size;

    dst = pic->data[0];

    /**
     * ZeroCodec has very simple interframe compression. If a value
     * is the same as the previous frame, set it to 0.
     */

    for (i = 0; i < avctx->height; i++) {
        zstream->next_out  = dst;
        zstream->avail_out = avctx->width << 1;

        zret = inflate(zstream, Z_SYNC_FLUSH);
        if (zret != Z_OK && zret != Z_STREAM_END) {
            avctx->release_buffer(avctx, pic);
            av_log(avctx, AV_LOG_ERROR,
                   "Inflate failed with return code: %d.\n", zret);
            return AVERROR_INVALIDDATA;
        }

        if (!(avpkt->flags & AV_PKT_FLAG_KEY))
            for (j = 0; j < avctx->width << 1; j++)
                dst[j] += prev[j] & -!dst[j];

        prev += prev_pic->linesize[0];
        dst  += pic->linesize[0];
    }

    /* Release the previous buffer if need be */
    if (prev_pic->data[0])
        avctx->release_buffer(avctx, prev_pic);

    *data_size       = sizeof(AVFrame);
    *(AVFrame *)data = *pic;

    /* Store the previous frame for use later.
     * FFSWAP ensures that e.g. pic->data is NULLed. */
    FFSWAP(AVFrame, *pic, *prev_pic);

    return avpkt->size;
}

static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
{
    ZeroCodecContext *zc = avctx->priv_data;
    AVFrame *prev_pic    = &zc->previous_frame;

    inflateEnd(&zc->zstream);

    /* Release last frame */
    if (prev_pic->data[0])
        avctx->release_buffer(avctx, prev_pic);

    av_freep(&avctx->coded_frame);

    return 0;
}

static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
{
    ZeroCodecContext *zc = avctx->priv_data;
    z_stream *zstream    = &zc->zstream;
    int zret;

    avctx->pix_fmt             = PIX_FMT_UYVY422;
    avctx->bits_per_raw_sample = 8;

    zc->size = avpicture_get_size(avctx->pix_fmt,
                                  avctx->width, avctx->height);

    zstream->zalloc = Z_NULL;
    zstream->zfree  = Z_NULL;
    zstream->opaque = Z_NULL;

    zret = inflateInit(zstream);
    if (zret != Z_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
        return AVERROR(ENOMEM);
    }

    avctx->coded_frame = avcodec_alloc_frame();
    if (!avctx->coded_frame) {
        av_log(avctx, AV_LOG_ERROR, "Could not allocate frame buffer.\n");
        zerocodec_decode_close(avctx);
        return AVERROR(ENOMEM);
    }

    return 0;
}

AVCodec ff_zerocodec_decoder = {
    .type           = AVMEDIA_TYPE_VIDEO,
    .name           = "zerocodec",
    .id             = AV_CODEC_ID_ZEROCODEC,
    .priv_data_size = sizeof(ZeroCodecContext),
    .init           = zerocodec_decode_init,
    .decode         = zerocodec_decode_frame,
    .close          = zerocodec_decode_close,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
};