cosmetics: Drop particularly redundant silly comments
[libav.git] / libavcodec / lclenc.c
1 /*
2 * LCL (LossLess Codec Library) Codec
3 * Copyright (c) 2002-2004 Roberto Togni
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * LCL (LossLess Codec Library) Video Codec
25 * Decoder for MSZH and ZLIB codecs
26 * Experimental encoder for ZLIB RGB24
27 *
28 * Fourcc: MSZH, ZLIB
29 *
30 * Original Win32 dll:
31 * Ver2.23 By Kenji Oshima 2000.09.20
32 * avimszh.dll, avizlib.dll
33 *
34 * A description of the decoding algorithm can be found here:
35 * http://www.pcisys.net/~melanson/codecs
36 *
37 * Supports: BGR24 (RGB 24bpp)
38 */
39
40 #include <stdio.h>
41 #include <stdlib.h>
42
43 #include "avcodec.h"
44 #include "internal.h"
45 #include "lcl.h"
46 #include "libavutil/internal.h"
47 #include "libavutil/mem.h"
48
49 #include <zlib.h>
50
51 typedef struct LclEncContext {
52
53 AVCodecContext *avctx;
54
55 // Image type
56 int imgtype;
57 // Compression type
58 int compression;
59 // Flags
60 int flags;
61 z_stream zstream;
62 } LclEncContext;
63
64 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
65 const AVFrame *pict, int *got_packet)
66 {
67 LclEncContext *c = avctx->priv_data;
68 const AVFrame * const p = pict;
69 int i, ret;
70 int zret; // Zlib return code
71 int max_size = deflateBound(&c->zstream, avctx->width * avctx->height * 3);
72
73 if (!pkt->data &&
74 (ret = av_new_packet(pkt, max_size)) < 0) {
75 av_log(avctx, AV_LOG_ERROR, "Error allocating packet of size %d.\n", max_size);
76 return ret;
77 }
78
79 if(avctx->pix_fmt != AV_PIX_FMT_BGR24){
80 av_log(avctx, AV_LOG_ERROR, "Format not supported!\n");
81 return -1;
82 }
83
84 zret = deflateReset(&c->zstream);
85 if (zret != Z_OK) {
86 av_log(avctx, AV_LOG_ERROR, "Deflate reset error: %d\n", zret);
87 return -1;
88 }
89 c->zstream.next_out = pkt->data;
90 c->zstream.avail_out = pkt->size;
91
92 for(i = avctx->height - 1; i >= 0; i--) {
93 c->zstream.next_in = p->data[0]+p->linesize[0]*i;
94 c->zstream.avail_in = avctx->width*3;
95 zret = deflate(&c->zstream, Z_NO_FLUSH);
96 if (zret != Z_OK) {
97 av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
98 return -1;
99 }
100 }
101 zret = deflate(&c->zstream, Z_FINISH);
102 if (zret != Z_STREAM_END) {
103 av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
104 return -1;
105 }
106
107 pkt->size = c->zstream.total_out;
108 pkt->flags |= AV_PKT_FLAG_KEY;
109 *got_packet = 1;
110
111 return 0;
112 }
113
114 static av_cold int encode_init(AVCodecContext *avctx)
115 {
116 LclEncContext *c = avctx->priv_data;
117 int zret; // Zlib return code
118
119 c->avctx= avctx;
120
121 assert(avctx->width && avctx->height);
122
123 avctx->extradata= av_mallocz(8);
124 if (!avctx->extradata)
125 return AVERROR(ENOMEM);
126
127 #if FF_API_CODED_FRAME
128 FF_DISABLE_DEPRECATION_WARNINGS
129 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
130 avctx->coded_frame->key_frame = 1;
131 FF_ENABLE_DEPRECATION_WARNINGS
132 #endif
133
134 // Will be user settable someday
135 c->compression = 6;
136 c->flags = 0;
137 c->imgtype = IMGTYPE_RGB24;
138 avctx->bits_per_coded_sample= 24;
139
140 avctx->extradata[0]= 4;
141 avctx->extradata[1]= 0;
142 avctx->extradata[2]= 0;
143 avctx->extradata[3]= 0;
144 avctx->extradata[4]= c->imgtype;
145 avctx->extradata[5]= c->compression;
146 avctx->extradata[6]= c->flags;
147 avctx->extradata[7]= CODEC_ZLIB;
148 c->avctx->extradata_size= 8;
149
150 c->zstream.zalloc = Z_NULL;
151 c->zstream.zfree = Z_NULL;
152 c->zstream.opaque = Z_NULL;
153 zret = deflateInit(&c->zstream, c->compression);
154 if (zret != Z_OK) {
155 av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
156 return AVERROR_UNKNOWN;
157 }
158
159 return 0;
160 }
161
162 static av_cold int encode_end(AVCodecContext *avctx)
163 {
164 LclEncContext *c = avctx->priv_data;
165
166 av_freep(&avctx->extradata);
167 deflateEnd(&c->zstream);
168
169 return 0;
170 }
171
172 AVCodec ff_zlib_encoder = {
173 .name = "zlib",
174 .long_name = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
175 .type = AVMEDIA_TYPE_VIDEO,
176 .id = AV_CODEC_ID_ZLIB,
177 .priv_data_size = sizeof(LclEncContext),
178 .init = encode_init,
179 .encode2 = encode_frame,
180 .close = encode_end,
181 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
182 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE |
183 FF_CODEC_CAP_INIT_CLEANUP,
184 };