Statistics
| Branch: | Revision:

ffmpeg / libavformat / flvenc.c @ 2f5132e7

History | View | Annotate | Download (4.71 KB)

1
/*
2
 * FLV encoder.
3
 * Copyright (c) 2003 The FFmpeg Project.
4
 *
5
 * This library is free software; you can redistribute it and/or
6
 * modify it under the terms of the GNU Lesser General Public
7
 * License as published by the Free Software Foundation; either
8
 * version 2 of the License, or (at your option) any later version.
9
 *
10
 * This library is distributed in the hope that it will be useful,
11
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13
 * Lesser General Public License for more details.
14
 *
15
 * You should have received a copy of the GNU Lesser General Public
16
 * License along with this library; if not, write to the Free Software
17
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18
 */
19
#include "avformat.h"
20

    
21
#undef NDEBUG
22
#include <assert.h>
23

    
24
typedef struct FLVContext {
25
    int hasAudio;
26
    int hasVideo;
27
    int reserved;
28
} FLVContext;
29

    
30
static void put_be24(ByteIOContext *pb, int value)
31
{
32
    put_byte(pb, (value>>16) & 0xFF );
33
    put_byte(pb, (value>> 8) & 0xFF );
34
    put_byte(pb, (value>> 0) & 0xFF );
35
}
36

    
37
static int get_audio_flags(AVCodecContext *enc){
38
    int flags = (enc->bits_per_sample == 16) ? 0x2 : 0x0;
39

    
40
    switch (enc->sample_rate) {
41
        case    44100:
42
            flags |= 0x0C;
43
            break;
44
        case    22050:
45
            flags |= 0x08;
46
            break;
47
        case    11025:
48
            flags |= 0x04;
49
            break;
50
        case     8000: //nellymoser only
51
        case     5512: //not mp3
52
            flags |= 0x00;
53
            break;
54
        default:
55
            return -1;
56
    }
57

    
58
    if (enc->channels > 1) {
59
        flags |= 0x01;
60
    }
61
    
62
    switch(enc->codec_id){
63
    case CODEC_ID_MP3:
64
        flags |= 0x20 | 0x2;
65
        break;
66
    case CODEC_ID_PCM_S8:
67
        break;
68
    case CODEC_ID_PCM_S16BE:
69
        flags |= 0x60 | 0x2;
70
        break;
71
    case CODEC_ID_PCM_S16LE:
72
        flags |= 0x2;
73
        break;
74
    case 0:
75
        flags |= enc->codec_tag<<4;
76
        break;
77
    default:
78
        return -1;
79
    }
80
    
81
    return flags;
82
}
83

    
84
static int flv_write_header(AVFormatContext *s)
85
{
86
    ByteIOContext *pb = &s->pb;
87
    FLVContext *flv = s->priv_data;
88
    int i;
89

    
90
    flv->hasAudio = 0;
91
    flv->hasVideo = 0;
92

    
93
    put_tag(pb,"FLV");
94
    put_byte(pb,1);
95
    put_byte(pb,0); // delayed write
96
    put_be32(pb,9);
97
    put_be32(pb,0);
98
    
99
    for(i=0; i<s->nb_streams; i++){
100
        AVCodecContext *enc = &s->streams[i]->codec;
101
        av_set_pts_info(s->streams[i], 24, 1, 1000); /* 24 bit pts in ms */
102
        if(enc->codec_tag == 5){
103
            put_byte(pb,8); // message type
104
            put_be24(pb,0); // include flags
105
            put_be24(pb,0); // time stamp
106
            put_be32(pb,0); // reserved
107
            put_be32(pb,11); // size
108
            flv->reserved=5;
109
        }
110
        if(enc->codec_type == CODEC_TYPE_AUDIO && get_audio_flags(enc)<0)
111
            return -1;
112
    }
113

    
114
    return 0;
115
}
116

    
117
static int flv_write_trailer(AVFormatContext *s)
118
{
119
    int64_t file_size;
120
    int flags = 0;
121

    
122
    ByteIOContext *pb = &s->pb;
123
    FLVContext *flv = s->priv_data;
124

    
125
    file_size = url_ftell(pb);
126
    flags |= flv->hasAudio ? 4 : 0;
127
    flags |= flv->hasVideo ? 1 : 0;
128
    url_fseek(pb, 4, SEEK_SET);
129
    put_byte(pb,flags);
130
    url_fseek(pb, file_size, SEEK_SET);
131
    return 0;
132
}
133

    
134
static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
135
{
136
    ByteIOContext *pb = &s->pb;
137
    AVCodecContext *enc = &s->streams[pkt->stream_index]->codec;
138
    FLVContext *flv = s->priv_data;
139
    int size= pkt->size;
140
    int flags;
141

    
142
//    av_log(s, AV_LOG_DEBUG, "type:%d pts: %lld size:%d\n", enc->codec_type, timestamp, size);
143
    
144
    if (enc->codec_type == CODEC_TYPE_VIDEO) {
145
        put_byte(pb, 9);
146
        flags = 2; // choose h263
147
        flags |= pkt->flags & PKT_FLAG_KEY ? 0x10 : 0x20; // add keyframe indicator
148
        flv->hasVideo = 1;
149
    } else {
150
        assert(enc->codec_type == CODEC_TYPE_AUDIO);
151
        flags = get_audio_flags(enc);
152
        
153
        assert(size);
154

    
155
        put_byte(pb, 8);
156

    
157
        // We got audio! Make sure we set this to the global flags on closure
158
        flv->hasAudio = 1;
159
    }
160

    
161
    put_be24(pb,size+1); // include flags
162
    put_be24(pb,pkt->pts);
163
    put_be32(pb,flv->reserved);
164
    put_byte(pb,flags);
165
    put_buffer(pb, pkt->data, size);
166
    put_be32(pb,size+1+11); // previous tag size
167
    
168
    put_flush_packet(pb);
169
    return 0;
170
}
171

    
172
static AVOutputFormat flv_oformat = {
173
    "flv",
174
    "flv format",
175
    "video/x-flashvideo",
176
    "flv",
177
    sizeof(FLVContext),
178
#ifdef CONFIG_MP3LAME
179
    CODEC_ID_MP3,
180
#else // CONFIG_MP3LAME
181
    CODEC_ID_NONE,
182
#endif // CONFIG_MP3LAME
183
    CODEC_ID_FLV1,
184
    flv_write_header,
185
    flv_write_packet,
186
    flv_write_trailer,
187
};
188

    
189
int flvenc_init(void)
190
{
191
    av_register_output_format(&flv_oformat);
192
    return 0;
193
}