PCM转MP3音频文件（借助lame库）

pcm2mp3.c

#include 
#include 
#include 

#define INBUFSIZE 4096
#define MP3BUFSIZE (int) (1.25 * INBUFSIZE) + 7200

int encode(char* inPath, char* outPath) 
{
	int status = 0;
	lame_global_flags* gfp;
	int ret_code;
	FILE* infp;
	FILE* outfp;
	short* input_buffer;
	int input_samples;
	char* mp3_buffer;
	int mp3_bytes;

	gfp = lame_init();
	if (gfp == NULL) 
	{
		printf("lame_init failed/n");
		status = -1;
		goto exit;
	}

	ret_code = lame_init_params(gfp);
	if (ret_code < 0) 
	{
		printf("lame_init_params returned %d/n",ret_code);
		status = -1;
		goto close_lame;
	}

	infp = fopen(inPath, "rb");
	outfp = fopen(outPath, "wb");

	input_buffer = (short*)malloc(INBUFSIZE*2);
	mp3_buffer = (char*)malloc(MP3BUFSIZE);

	do
	{
		input_samples = fread(input_buffer, 2, INBUFSIZE, infp);
		printf("input_samples is %d./n",input_samples);
		//fprintf(stderr, "input_samples is %d./n", input_samples);
		mp3_bytes = lame_encode_buffer_interleaved(gfp, input_buffer,input_samples/2, mp3_buffer, MP3BUFSIZE);
		//fprintf(stderr, "mp3_bytes is %d./n", mp3_bytes);
		if (mp3_bytes < 0) 
		{
			printf("lame_encode_buffer_interleaved returned %d/n", mp3_bytes);
			status = -1;
			goto free_buffers;
		} 
		else if(mp3_bytes > 0) 
		{
			fwrite(mp3_buffer, 1, mp3_bytes, outfp);
		}
	}while (input_samples == INBUFSIZE);

	mp3_bytes = lame_encode_flush(gfp, mp3_buffer, sizeof(mp3_buffer));
	if (mp3_bytes > 0) 
	{
		printf("writing %d mp3 bytes/n", mp3_bytes);
		fwrite(mp3_buffer, 1, mp3_bytes, outfp);
	}
free_buffers:
	free(mp3_buffer);
	free(input_buffer);

	fclose(outfp);
	fclose(infp);
close_lame:
	lame_close(gfp);
exit:
	return status;
}

int main(int argc, char** argv) 
{
	if (argc < 3) 
	{
		printf("usage: lame_test rawinfile mp3outfile/n");
	}
	encode(argv[1], argv[2]);
	return 0;
}