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 
27 typedef struct ZeroCodecContext {
28     AVFrame  *previous_frame;
29     FFZStream zstream;
30 } ZeroCodecContext;
31 
zerocodec_decode_frame(AVCodecContext *avctx, AVFrame *pic, int *got_frame, AVPacket *avpkt)32 static 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 
zerocodec_decode_close(AVCodecContext *avctx)104 static 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 
zerocodec_decode_init(AVCodecContext *avctx)115 static 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 
zerocodec_decode_flush(AVCodecContext *avctx)129 static void zerocodec_decode_flush(AVCodecContext *avctx)
130 {
131     ZeroCodecContext *zc = avctx->priv_data;
132 
133     av_frame_unref(zc->previous_frame);
134 }
135 
136 const 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