下午好。 对不起,我的英语不是很好。
有些日子,我试图将WAV转换为MP3。 为此,我使用LAME。 我可以使用以下命令通过命令提示符转换文件:
lame.exe-B128 - resample 8-mj \ "C: \ \ test.wav \" \ "C: \ \ test.mp3 \"
但我不想通过命令行(跨操作系统的可移植性),但我不能用C ++(通过LAME库)来实现。
这是我的代码:
int main()
{
//...
//...
// extraction of PCM audio data file .wav in file.pcm
short read, write;
FILE *pcm = fopen("file.pcm", "rb");
FILE *mp3 = fopen("file.mp3", "wb");
const int PCM_SIZE = 18424;
const int MP3_SIZE = 13424;
short int pcm_buffer[PCM_SIZE];
unsigned char mp3_buffer[MP3_SIZE];
lame_t lame = lame_init();
if ( lame == NULL ) {
cout<<"Unable to initialize MP3"<<endl;
return -1;
}
lame_set_num_channels(lame, 1);
lame_set_in_samplerate(lame, 8000);
lame_set_out_samplerate(lame, 8000);
lame_set_brate(lame, 128);
lame_set_mode(lame, MONO);
lame_set_quality(lame, 2);
lame_set_bWriteVbrTag(lame, 0);
if (( lame_init_params(lame)) < 0) {
cout << "Unable to initialize MP3 parameters"<<endl;
return -1;
}
do {
read = fread(pcm_buffer,sizeof(short), PCM_SIZE, pcm);
if (read == 0)
write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
else
write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, MP3_SIZE);
fwrite(mp3_buffer, write, 1, mp3);
} while (read != 0);
lame_close(lame);
fclose(mp3);
fclose(pcm);
return 0;
}
我收到质量非常差的MP3文件(持续时间比原始文件短)。
任何解决问题的想法?
这是我的信息。
Wav:
- Frequency= 8000
- BlocSize= 16
- Canal Nomber= 1 (mono)
- BytePerSec= 16000
- BytePerBloc= 2
- BitsPerSample= 16
- Bitrate= 128
- .wav size: 13466 (ie size of PCM: 13422)
谢谢。
答案 0 :(得分:3)
@try
{
int read, write;
FILE *pcm = fopen([cafFilePath cStringUsingEncoding:1], "rb"); //source
fseek(pcm, 4*1024, SEEK_CUR); //skip file header
mp3 = fopen([mp3FilePath cStringUsingEncoding:1], "wb"); //output
const int PCM_SIZE = 8192*3;
const int MP3_SIZE = 8192*3;
short int pcm_buffer[PCM_SIZE*2];
unsigned char mp3_buffer[MP3_SIZE];
lame_t lame = lame_init();
lame_set_in_samplerate(lame, 11025*2);
lame_set_VBR(lame, vbr_default);
lame_init_params(lame);
int nTotalRead=0;
do {
read = fread(pcm_buffer, 2*sizeof(short int), PCM_SIZE, pcm);
nTotalRead+=read*4;
if (read == 0)
write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
else
write = lame_encode_buffer_interleaved(lame,pcm_buffer, read, mp3_buffer, MP3_SIZE);
// write = lame_encode_buffer(lame, pcm_buffer,pcm_buffer, read, mp3_buffer, MP3_SIZE);
fwrite(mp3_buffer, write, 1, mp3);
} while (read != 0);
lame_close(lame);
fclose(mp3);
fclose(pcm);
}
@catch (NSException *exception)
{
NSLog(@"%@",[exception description]);
}