xref: /third_party/ffmpeg/libavcodec/zerocodec.c (revision cabdff1a) 
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 "internal.h"
24#include "zlib_wrapper.h"
25#include "libavutil/common.h"
26
27typedef struct ZeroCodecContext {
28    AVFrame  *previous_frame;
29    FFZStream zstream;
30} ZeroCodecContext;
31
32static int zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic,
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->key_frame = 1;
44        pic->pict_type = AV_PICTURE_TYPE_I;
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->key_frame = 0;
54        pic->pict_type = AV_PICTURE_TYPE_P;
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
91        prev -= prev_pic->linesize[0];
92        dst  -= pic->linesize[0];
93    }
94
95    av_frame_unref(zc->previous_frame);
96    if ((ret = av_frame_ref(zc->previous_frame, pic)) < 0)
97        return ret;
98
99    *got_frame = 1;
100
101    return avpkt->size;
102}
103
104static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
105{
106    ZeroCodecContext *zc = avctx->priv_data;
107
108    av_frame_free(&zc->previous_frame);
109
110    ff_inflate_end(&zc->zstream);
111
112    return 0;
113}
114
115static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
116{
117    ZeroCodecContext *zc = avctx->priv_data;
118
119    avctx->pix_fmt             = AV_PIX_FMT_UYVY422;
120    avctx->bits_per_raw_sample = 8;
121
122    zc->previous_frame = av_frame_alloc();
123    if (!zc->previous_frame)
124        return AVERROR(ENOMEM);
125
126    return ff_inflate_init(&zc->zstream, avctx);
127}
128
129static void zerocodec_decode_flush(AVCodecContext *avctx)
130{
131    ZeroCodecContext *zc = avctx->priv_data;
132
133    av_frame_unref(zc->previous_frame);
134}
135
136const FFCodec ff_zerocodec_decoder = {
137    .p.type         = AVMEDIA_TYPE_VIDEO,
138    .p.name         = "zerocodec",
139    .p.long_name    = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
140    .p.id           = AV_CODEC_ID_ZEROCODEC,
141    .priv_data_size = sizeof(ZeroCodecContext),
142    .init           = zerocodec_decode_init,
143    FF_CODEC_DECODE_CB(zerocodec_decode_frame),
144    .flush          = zerocodec_decode_flush,
145    .close          = zerocodec_decode_close,
146    .p.capabilities = AV_CODEC_CAP_DR1,
147    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
148                      FF_CODEC_CAP_INIT_CLEANUP,
149};
150