/*
?*?decode.c
?*
?*?CCITT?ADPCM?decoder
?*
?*?Usage?:?decode?[-3|4|5]?[-a|u|l]??outfile
?*/
#include?
#include?“g72x.h“


/*
?*?Unpack?input?codes?and?pass?them?back?as?bytes.
?*?Returns?1?if?there?is?residual?input?returns?-1?if?eof?else?returns?0.
?*/
int
unpack_input（
	unsigned?char		*code
	int			bits）
{
	static?unsigned?int	in_buffer?=?0;
	static?int		in_bits?=?0;
	unsigned?char		in_byte;

	if?（in_bits?		if?（fread（&in_byte?sizeof?（char）?1?stdin）?!=?1）?{
			*code?=?0;
			return?（-1）;
		}
		in_buffer?|=?（in_byte?<		in_bits?+=?8;
	}
	*code?=?in_buffer?&?（（1?<	in_buffer?>>=?bits;
	in_bits?-=?bits;
	return?（in_bits?>?0）;
}


main（
	int			argc
	char			**argv）
{
	short			sample;
	unsigned?char		code;
	int			n;
	struct?g72x_state	state;
	int			out_coding;
	int			out_size;
	int			（*dec_routine）（）;
	int			dec_bits;

	g72x_init_state（&state）;
	out_coding?=?AUDIO_ENCODING_ULAW;
	out_size?=?sizeof?（char）;
	dec_routine?=?g721_decoder;
	dec_bits?=?4;

	/*?Process?encoding?argument?if?any?*/
	while?（（argc?>?1）?&&?（argv[1][0]?==?‘-‘））?{
		switch?（argv[1][1]）?{
		case?‘3‘:
			dec_routine?=?g723_24_decoder;
			dec_bits?=?3;
			break;
		case?‘4‘:
			dec_routine?=?g721_decoder;
			dec_bits?=?4;
			break;
		case?‘5‘:
			dec_routine?=?g723_40_decoder;
			dec_bits?=?5;
			break;
		case?‘u‘:
			out_coding?=?AUDIO_ENCODING_ULAW;
			out_size?=?sizeof?（char）;
			break;
		case?‘a‘:
			out_coding?=?AUDIO_ENCODING_ALAW;
			out_size?=?sizeof?（char）;
			break;
		case?‘l‘:
			out_coding?=?AUDIO_ENCODING_LINEAR;
			out_size?=?sizeof?（short）;
			break;
		default:
fprintf（stderr?“CCITT?ADPCM?Decoder?--?usage:\n“）;
fprintf（stderr?“\tdecode?[-3|4|5]?[-a|u|l]??outfile\n“）;
fprintf（stderr?“where:\n“）;
fprintf（stderr?“\t-3\tProcess?G.723?24kbps?（3-bit）?input?data\n“）;
fprintf（stderr?“\t-4\tProcess?G.721?32kbps?（4-bit）?input?data?[default]\n“）;
fprintf（stderr?“\t-5\tProcess?G.723?40kbps?（5-bit）?input?data\n“）;
fprintf（stderr?“\t-a\tGenerate?8-bit?A-law?data\n“）;
fprintf（stderr?“\t-u\tGenerate?8-bit?u-law?data?[default]\n“）;
fprintf（stderr?“\t-l\tGenerate?16-bit?linear?PCM?data\n“）;
			exit（1）;
		}
		argc--;
		argv++;
	}

	/*?Read?and?unpack?input?codes?and?process?them?*/
	while?（unpack_input（&code?dec_bits）?>=?0）?{
		sample?=?（*dec_routine）（code?out_coding?&state）;
		if?（out_size?==?2）?{
			fwrite（&sample?out_size?1?stdout）;
		}?else?{
			code?=?（unsigned?char）sample;
			fwrite（&code?out_size?1?stdout）;
		}
	}
	fclose（stdout）;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????5707??1992-09-01?06:09??g723_40.c

?????文件????????603??1992-09-01?06:09??Makefile

?????文件???????3311??1992-09-01?06:09??README

?????文件???????2640??1992-09-01?06:09??decode.c

?????文件???????2866??1992-09-01?06:09??encode.c

?????文件??????14948??1992-09-01?06:09??g72x.c

?????文件???????3438??1992-09-01?06:09??g72x.h

?????文件???????7804??1992-09-01?06:09??g711.c

?????文件???????5430??1992-09-01?06:09??g721.c

?????文件???????4795??1992-09-01?06:09??g723_24.c

?????文件????????229??2007-09-18?11:49??www.mp4tech.net便攜式多媒體技術中心.txt

-----------?---------??----------?-----??----

????????????????51771????????????????????11