ffmpeg/libavformat/mp3.c
Reimar Döffinger 89ecc26188 Fix two small typos in comment
Originally committed as revision 8920 to svn://svn.ffmpeg.org/ffmpeg/trunk
2007-05-06 18:23:28 +00:00

429 lines
10 KiB
C

/*
* MP3 muxer and demuxer
* Copyright (c) 2003 Fabrice Bellard.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "mpegaudio.h"
#define ID3_HEADER_SIZE 10
#define ID3_TAG_SIZE 128
#define ID3_GENRE_MAX 125
static const char *id3_genre_str[ID3_GENRE_MAX + 1] = {
[0] = "Blues",
[1] = "Classic Rock",
[2] = "Country",
[3] = "Dance",
[4] = "Disco",
[5] = "Funk",
[6] = "Grunge",
[7] = "Hip-Hop",
[8] = "Jazz",
[9] = "Metal",
[10] = "New Age",
[11] = "Oldies",
[12] = "Other",
[13] = "Pop",
[14] = "R&B",
[15] = "Rap",
[16] = "Reggae",
[17] = "Rock",
[18] = "Techno",
[19] = "Industrial",
[20] = "Alternative",
[21] = "Ska",
[22] = "Death Metal",
[23] = "Pranks",
[24] = "Soundtrack",
[25] = "Euro-Techno",
[26] = "Ambient",
[27] = "Trip-Hop",
[28] = "Vocal",
[29] = "Jazz+Funk",
[30] = "Fusion",
[31] = "Trance",
[32] = "Classical",
[33] = "Instrumental",
[34] = "Acid",
[35] = "House",
[36] = "Game",
[37] = "Sound Clip",
[38] = "Gospel",
[39] = "Noise",
[40] = "AlternRock",
[41] = "Bass",
[42] = "Soul",
[43] = "Punk",
[44] = "Space",
[45] = "Meditative",
[46] = "Instrumental Pop",
[47] = "Instrumental Rock",
[48] = "Ethnic",
[49] = "Gothic",
[50] = "Darkwave",
[51] = "Techno-Industrial",
[52] = "Electronic",
[53] = "Pop-Folk",
[54] = "Eurodance",
[55] = "Dream",
[56] = "Southern Rock",
[57] = "Comedy",
[58] = "Cult",
[59] = "Gangsta",
[60] = "Top 40",
[61] = "Christian Rap",
[62] = "Pop/Funk",
[63] = "Jungle",
[64] = "Native American",
[65] = "Cabaret",
[66] = "New Wave",
[67] = "Psychadelic",
[68] = "Rave",
[69] = "Showtunes",
[70] = "Trailer",
[71] = "Lo-Fi",
[72] = "Tribal",
[73] = "Acid Punk",
[74] = "Acid Jazz",
[75] = "Polka",
[76] = "Retro",
[77] = "Musical",
[78] = "Rock & Roll",
[79] = "Hard Rock",
[80] = "Folk",
[81] = "Folk-Rock",
[82] = "National Folk",
[83] = "Swing",
[84] = "Fast Fusion",
[85] = "Bebob",
[86] = "Latin",
[87] = "Revival",
[88] = "Celtic",
[89] = "Bluegrass",
[90] = "Avantgarde",
[91] = "Gothic Rock",
[92] = "Progressive Rock",
[93] = "Psychedelic Rock",
[94] = "Symphonic Rock",
[95] = "Slow Rock",
[96] = "Big Band",
[97] = "Chorus",
[98] = "Easy Listening",
[99] = "Acoustic",
[100] = "Humour",
[101] = "Speech",
[102] = "Chanson",
[103] = "Opera",
[104] = "Chamber Music",
[105] = "Sonata",
[106] = "Symphony",
[107] = "Booty Bass",
[108] = "Primus",
[109] = "Porn Groove",
[110] = "Satire",
[111] = "Slow Jam",
[112] = "Club",
[113] = "Tango",
[114] = "Samba",
[115] = "Folklore",
[116] = "Ballad",
[117] = "Power Ballad",
[118] = "Rhythmic Soul",
[119] = "Freestyle",
[120] = "Duet",
[121] = "Punk Rock",
[122] = "Drum Solo",
[123] = "A capella",
[124] = "Euro-House",
[125] = "Dance Hall",
};
/* buf must be ID3_HEADER_SIZE byte long */
static int id3_match(const uint8_t *buf)
{
return (buf[0] == 'I' &&
buf[1] == 'D' &&
buf[2] == '3' &&
buf[3] != 0xff &&
buf[4] != 0xff &&
(buf[6] & 0x80) == 0 &&
(buf[7] & 0x80) == 0 &&
(buf[8] & 0x80) == 0 &&
(buf[9] & 0x80) == 0);
}
static void id3_get_string(char *str, int str_size,
const uint8_t *buf, int buf_size)
{
int i, c;
char *q;
q = str;
for(i = 0; i < buf_size; i++) {
c = buf[i];
if (c == '\0')
break;
if ((q - str) >= str_size - 1)
break;
*q++ = c;
}
*q = '\0';
}
/* 'buf' must be ID3_TAG_SIZE byte long */
static int id3_parse_tag(AVFormatContext *s, const uint8_t *buf)
{
char str[5];
int genre;
if (!(buf[0] == 'T' &&
buf[1] == 'A' &&
buf[2] == 'G'))
return -1;
id3_get_string(s->title, sizeof(s->title), buf + 3, 30);
id3_get_string(s->author, sizeof(s->author), buf + 33, 30);
id3_get_string(s->album, sizeof(s->album), buf + 63, 30);
id3_get_string(str, sizeof(str), buf + 93, 4);
s->year = atoi(str);
id3_get_string(s->comment, sizeof(s->comment), buf + 97, 30);
if (buf[125] == 0 && buf[126] != 0)
s->track = buf[126];
genre = buf[127];
if (genre <= ID3_GENRE_MAX)
pstrcpy(s->genre, sizeof(s->genre), id3_genre_str[genre]);
return 0;
}
static void id3_create_tag(AVFormatContext *s, uint8_t *buf)
{
int v, i;
memset(buf, 0, ID3_TAG_SIZE); /* fail safe */
buf[0] = 'T';
buf[1] = 'A';
buf[2] = 'G';
strncpy(buf + 3, s->title, 30);
strncpy(buf + 33, s->author, 30);
strncpy(buf + 63, s->album, 30);
v = s->year;
if (v > 0) {
for(i = 0;i < 4; i++) {
buf[96 - i] = '0' + (v % 10);
v = v / 10;
}
}
strncpy(buf + 97, s->comment, 30);
if (s->track != 0) {
buf[125] = 0;
buf[126] = s->track;
}
for(i = 0; i <= ID3_GENRE_MAX; i++) {
if (!strcasecmp(s->genre, id3_genre_str[i])) {
buf[127] = i;
break;
}
}
}
/* mp3 read */
static int mp3_read_probe(AVProbeData *p)
{
int max_frames, first_frames;
int fsize, frames, sample_rate;
uint32_t header;
uint8_t *buf, *buf2, *end;
AVCodecContext avctx;
if(id3_match(p->buf))
return AVPROBE_SCORE_MAX/2+1; // this must be less than mpeg-ps because some retards put id3 tags before mpeg-ps files
max_frames = 0;
buf = p->buf;
end = buf + FFMIN(4096, p->buf_size - sizeof(uint32_t));
for(; buf < end; buf++) {
buf2 = buf;
for(frames = 0; buf2 < end; frames++) {
header = (buf2[0] << 24) | (buf2[1] << 16) | (buf2[2] << 8) | buf2[3];
fsize = mpa_decode_header(&avctx, header, &sample_rate);
if(fsize < 0)
break;
buf2 += fsize;
}
max_frames = FFMAX(max_frames, frames);
if(buf == p->buf)
first_frames= frames;
}
if (first_frames>=3) return AVPROBE_SCORE_MAX/2+1;
else if(max_frames>=3) return AVPROBE_SCORE_MAX/4;
else if(max_frames>=1) return 1;
else return 0;
}
static int mp3_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
AVStream *st;
uint8_t buf[ID3_TAG_SIZE];
int len, ret, filesize;
st = av_new_stream(s, 0);
if (!st)
return AVERROR_NOMEM;
st->codec->codec_type = CODEC_TYPE_AUDIO;
st->codec->codec_id = CODEC_ID_MP3;
st->need_parsing = AVSTREAM_PARSE_FULL;
/* try to get the TAG */
if (!url_is_streamed(&s->pb)) {
/* XXX: change that */
filesize = url_fsize(&s->pb);
if (filesize > 128) {
url_fseek(&s->pb, filesize - 128, SEEK_SET);
ret = get_buffer(&s->pb, buf, ID3_TAG_SIZE);
if (ret == ID3_TAG_SIZE) {
id3_parse_tag(s, buf);
}
url_fseek(&s->pb, 0, SEEK_SET);
}
}
/* if ID3 header found, skip it */
ret = get_buffer(&s->pb, buf, ID3_HEADER_SIZE);
if (ret != ID3_HEADER_SIZE)
return -1;
if (id3_match(buf)) {
/* skip ID3 header */
len = ((buf[6] & 0x7f) << 21) |
((buf[7] & 0x7f) << 14) |
((buf[8] & 0x7f) << 7) |
(buf[9] & 0x7f);
url_fskip(&s->pb, len);
} else {
url_fseek(&s->pb, 0, SEEK_SET);
}
/* the parameters will be extracted from the compressed bitstream */
return 0;
}
#define MP3_PACKET_SIZE 1024
static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret, size;
// AVStream *st = s->streams[0];
size= MP3_PACKET_SIZE;
ret= av_get_packet(&s->pb, pkt, size);
pkt->stream_index = 0;
if (ret <= 0) {
return AVERROR_IO;
}
/* note: we need to modify the packet size here to handle the last
packet */
pkt->size = ret;
return ret;
}
static int mp3_read_close(AVFormatContext *s)
{
return 0;
}
#ifdef CONFIG_MUXERS
/* simple formats */
static int mp3_write_header(struct AVFormatContext *s)
{
return 0;
}
static int mp3_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
put_buffer(&s->pb, pkt->data, pkt->size);
put_flush_packet(&s->pb);
return 0;
}
static int mp3_write_trailer(struct AVFormatContext *s)
{
uint8_t buf[ID3_TAG_SIZE];
/* write the id3 header */
if (s->title[0] != '\0') {
id3_create_tag(s, buf);
put_buffer(&s->pb, buf, ID3_TAG_SIZE);
put_flush_packet(&s->pb);
}
return 0;
}
#endif //CONFIG_MUXERS
#ifdef CONFIG_MP3_DEMUXER
AVInputFormat mp3_demuxer = {
"mp3",
"MPEG audio",
0,
mp3_read_probe,
mp3_read_header,
mp3_read_packet,
mp3_read_close,
.flags= AVFMT_GENERIC_INDEX,
.extensions = "mp2,mp3,m2a", /* XXX: use probe */
};
#endif
#ifdef CONFIG_MP2_MUXER
AVOutputFormat mp2_muxer = {
"mp2",
"MPEG audio layer 2",
"audio/x-mpeg",
#ifdef CONFIG_LIBMP3LAME
"mp2,m2a",
#else
"mp2,mp3,m2a",
#endif
0,
CODEC_ID_MP2,
0,
mp3_write_header,
mp3_write_packet,
mp3_write_trailer,
};
#endif
#ifdef CONFIG_MP3_MUXER
AVOutputFormat mp3_muxer = {
"mp3",
"MPEG audio layer 3",
"audio/x-mpeg",
"mp3",
0,
CODEC_ID_MP3,
0,
mp3_write_header,
mp3_write_packet,
mp3_write_trailer,
};
#endif