FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
lclenc.c
Go to the documentation of this file.
1 /*
2  * LCL (LossLess Codec Library) Codec
3  * Copyright (c) 2002-2004 Roberto Togni
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 
41 #include <stdio.h>
42 #include <stdlib.h>
43 
44 #include "libavutil/avassert.h"
45 #include "avcodec.h"
46 #include "internal.h"
47 #include "lcl.h"
48 #include "libavutil/internal.h"
49 #include "libavutil/mem.h"
50 
51 #include <zlib.h>
52 
53 /*
54  * Decoder context
55  */
56 typedef struct LclEncContext {
57 
59 
60  // Image type
61  int imgtype;
62  // Compression type
64  // Flags
65  int flags;
66  z_stream zstream;
68 
69 /*
70  *
71  * Encode a frame
72  *
73  */
75  const AVFrame *p, int *got_packet)
76 {
77  LclEncContext *c = avctx->priv_data;
78  int i, ret;
79  int zret; // Zlib return code
80  int max_size = deflateBound(&c->zstream, avctx->width * avctx->height * 3);
81 
82  if ((ret = ff_alloc_packet2(avctx, pkt, max_size)) < 0)
83  return ret;
84 
85  if(avctx->pix_fmt != AV_PIX_FMT_BGR24){
86  av_log(avctx, AV_LOG_ERROR, "Format not supported!\n");
87  return -1;
88  }
89 
90  zret = deflateReset(&c->zstream);
91  if (zret != Z_OK) {
92  av_log(avctx, AV_LOG_ERROR, "Deflate reset error: %d\n", zret);
93  return -1;
94  }
95  c->zstream.next_out = pkt->data;
96  c->zstream.avail_out = pkt->size;
97 
98  for(i = avctx->height - 1; i >= 0; i--) {
99  c->zstream.next_in = p->data[0]+p->linesize[0]*i;
100  c->zstream.avail_in = avctx->width*3;
101  zret = deflate(&c->zstream, Z_NO_FLUSH);
102  if (zret != Z_OK) {
103  av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
104  return -1;
105  }
106  }
107  zret = deflate(&c->zstream, Z_FINISH);
108  if (zret != Z_STREAM_END) {
109  av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
110  return -1;
111  }
112 
113  pkt->size = c->zstream.total_out;
114  pkt->flags |= AV_PKT_FLAG_KEY;
115  *got_packet = 1;
116 
117  return 0;
118 }
119 
120 /*
121  *
122  * Init lcl encoder
123  *
124  */
126 {
127  LclEncContext *c = avctx->priv_data;
128  int zret; // Zlib return code
129 
130  c->avctx= avctx;
131 
132  av_assert0(avctx->width && avctx->height);
133 
135  if (!avctx->extradata)
136  return AVERROR(ENOMEM);
137 
138  avctx->coded_frame = av_frame_alloc();
139  if (!avctx->coded_frame)
140  return AVERROR(ENOMEM);
141 
143  avctx->coded_frame->key_frame = 1;
144 
147  av_clip(avctx->compression_level, 0, 9);
148  c->flags = 0;
149  c->imgtype = IMGTYPE_RGB24;
150  avctx->bits_per_coded_sample= 24;
151 
152  avctx->extradata[0]= 4;
153  avctx->extradata[1]= 0;
154  avctx->extradata[2]= 0;
155  avctx->extradata[3]= 0;
156  avctx->extradata[4]= c->imgtype;
157  avctx->extradata[5]= c->compression;
158  avctx->extradata[6]= c->flags;
159  avctx->extradata[7]= CODEC_ZLIB;
160  c->avctx->extradata_size= 8;
161 
162  c->zstream.zalloc = Z_NULL;
163  c->zstream.zfree = Z_NULL;
164  c->zstream.opaque = Z_NULL;
165  zret = deflateInit(&c->zstream, c->compression);
166  if (zret != Z_OK) {
167  av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
168  return 1;
169  }
170 
171  return 0;
172 }
173 
174 /*
175  *
176  * Uninit lcl encoder
177  *
178  */
180 {
181  LclEncContext *c = avctx->priv_data;
182 
183  av_freep(&avctx->extradata);
184  deflateEnd(&c->zstream);
185 
186  av_frame_free(&avctx->coded_frame);
187 
188  return 0;
189 }
190 
192  .name = "zlib",
193  .long_name = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
194  .type = AVMEDIA_TYPE_VIDEO,
195  .id = AV_CODEC_ID_ZLIB,
196  .priv_data_size = sizeof(LclEncContext),
197  .init = encode_init,
198  .encode2 = encode_frame,
199  .close = encode_end,
200  .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
201 };