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 ZeroCodecContext {
26     AVFrame  *previous_frame;
27     z_stream zstream;
28 } ZeroCodecContext;
29 
zerocodec_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)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;
43         pic->pict_type = AV_PICTURE_TYPE_I;
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;
53         pic->pict_type = AV_PICTURE_TYPE_P;
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 ((ret = ff_get_buffer(avctx, pic, AV_GET_BUFFER_FLAG_REF)) < 0)
63         return ret;
64 
65     zstream->next_in  = avpkt->data;
66     zstream->avail_in = avpkt->size;
67 
68     dst = pic->data[0] + (avctx->height - 1) * pic->linesize[0];
69 
70     /**
71      * ZeroCodec has very simple interframe compression. If a value
72      * is the same as the previous frame, set it to 0.
73      */
74 
75     for (i = 0; i < avctx->height; i++) {
76         zstream->next_out  = dst;
77         zstream->avail_out = avctx->width << 1;
78 
79         zret = inflate(zstream, Z_SYNC_FLUSH);
80         if (zret != Z_OK && zret != Z_STREAM_END) {
81             av_log(avctx, AV_LOG_ERROR,
82                    "Inflate failed with return code: %d.\n", zret);
83             return AVERROR_INVALIDDATA;
84         }
85 
86         if (!(avpkt->flags & AV_PKT_FLAG_KEY))
87             for (j = 0; j < avctx->width << 1; j++)
88                 dst[j] += prev[j] & -!dst[j];
89 
90         prev -= prev_pic->linesize[0];
91         dst  -= pic->linesize[0];
92     }
93 
94     av_frame_unref(zc->previous_frame);
95     if ((ret = av_frame_ref(zc->previous_frame, pic)) < 0)
96         return ret;
97 
98     *got_frame = 1;
99 
100     return avpkt->size;
101 }
102 
zerocodec_decode_close(AVCodecContext * avctx)103 static av_cold int zerocodec_decode_close(AVCodecContext *avctx)
104 {
105     ZeroCodecContext *zc = avctx->priv_data;
106 
107     av_frame_free(&zc->previous_frame);
108 
109     inflateEnd(&zc->zstream);
110 
111     return 0;
112 }
113 
zerocodec_decode_init(AVCodecContext * avctx)114 static av_cold int zerocodec_decode_init(AVCodecContext *avctx)
115 {
116     ZeroCodecContext *zc = avctx->priv_data;
117     z_stream *zstream    = &zc->zstream;
118     int zret;
119 
120     avctx->pix_fmt             = AV_PIX_FMT_UYVY422;
121     avctx->bits_per_raw_sample = 8;
122 
123     zstream->zalloc = Z_NULL;
124     zstream->zfree  = Z_NULL;
125     zstream->opaque = Z_NULL;
126 
127     zret = inflateInit(zstream);
128     if (zret != Z_OK) {
129         av_log(avctx, AV_LOG_ERROR, "Could not initialize inflate: %d.\n", zret);
130         return AVERROR(ENOMEM);
131     }
132 
133     zc->previous_frame = av_frame_alloc();
134     if (!zc->previous_frame)
135         return AVERROR(ENOMEM);
136 
137     return 0;
138 }
139 
zerocodec_decode_flush(AVCodecContext * avctx)140 static void zerocodec_decode_flush(AVCodecContext *avctx)
141 {
142     ZeroCodecContext *zc = avctx->priv_data;
143 
144     av_frame_unref(zc->previous_frame);
145 }
146 
147 AVCodec ff_zerocodec_decoder = {
148     .type           = AVMEDIA_TYPE_VIDEO,
149     .name           = "zerocodec",
150     .long_name      = NULL_IF_CONFIG_SMALL("ZeroCodec Lossless Video"),
151     .id             = AV_CODEC_ID_ZEROCODEC,
152     .priv_data_size = sizeof(ZeroCodecContext),
153     .init           = zerocodec_decode_init,
154     .decode         = zerocodec_decode_frame,
155     .flush          = zerocodec_decode_flush,
156     .close          = zerocodec_decode_close,
157     .capabilities   = AV_CODEC_CAP_DR1,
158     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
159                       FF_CODEC_CAP_INIT_CLEANUP,
160 };
161