#include <u.h>#include <libc.h>#include <bio.h>#include "common.h"#include "packet.h" static int ratecfg[] = {	96000,	88200,	64000,	48000,	44100,	32000,	24000,	22050,	16000,	12000,	11025,	8000,	7350,	-1,	-1,	-1,}; intaacpacket(Biobuf *out, Packetctx *ctx, Packet *p, int np, uvlong ts, int key){	int i, chanc, ratei, objt, sz;	u16int x;	char *c; 	USED(ts, key);	if(ctx->frid == 0){ /* set up ADTS */		ctx->adts[0] = 0xff; /* syncword */		ctx->adts[1] = 0xf1; /* syncword, mpeg4, no crc */		if(ctx->codec.priv.sz >= 2){ /* prefer code private data */			x = ctx->codec.priv.data[0]<<8 | ctx->codec.priv.data[1];			chanc = (x>>3) & 0xf;			ratei = (x>>7) & 0xf;			objt = x>>11;			if(chanc > 7){				werrstr("channel config out of range: %d", chanc);				goto err;			}			if(ratecfg[ratei] < 1){				werrstr("invalid rate config: %d", ratei);				goto err;			}			if(objt > 4){				werrstr("object type out of range: %d", objt);				goto err;			}		}else{			for(ratei = 0; ratei < nelem(ratecfg) && ratecfg[ratei] != ctx->audio.samplerate; ratei++);			if(ratei >= nelem(ratecfg) || ratecfg[ratei] < 1){				werrstr("unsupported sample rate: %d", (int)ctx->audio.samplerate);				goto err;			} 			c = ctx->codec.name;			if(memcmp(c, "A_AAC/MPEG2/", 12) == 0){				ctx->adts[1] |= 1<<3;			}else if(memcmp(c, "A_AAC/MPEG4/", 12) != 0){badcodec:				werrstr("unsupported codec: %s", c);				goto err;			}			if(strcmp(c+12, "MAIN") == 0)				objt = 1;			else if(memcmp(c+12, "LC", 2) == 2 && (c[14] == 0 || strcmp(c+14, "/SBR") == 0))				objt = 2;			else if(strcmp(c+12, "SSR") == 0)				objt = 3;			else if(strcmp(c+12, "LTP") == 0)				objt = 4;			else				goto badcodec; 			if(ctx->audio.channels >= 1 && ctx->audio.channels <= 6)				chanc = ctx->audio.channels;			else if(ctx->audio.channels == 8)				chanc = 7;			else{ /* FIXME is it possible to use 0 and provide a custom channel config? */				werrstr("unsupported number of channels: %d", ctx->audio.channels);				goto err;			}		} 		ctx->adts[2] = (objt-1)<<6 | ratei<<2 | chanc>>2; /* object type, rate, channel config */		ctx->adts[3] = (chanc&3)<<6; /* channel config */		ctx->adts[6] = 0xfc; /* fullness, number of frames */	} 	for(i = 0; i < np; i++, p++){		sz = 7+p->sz;		ctx->adts[3] = ctx->adts[3]&(3<<6) | (sz>>11)&3; /* channels, frame length */		ctx->adts[4] = (sz>>3) & 0xff; /* frame length */		ctx->adts[5] = (sz&7)<<5 | 0x1f; /* frame length, fullness */		if(Bwrite(out, ctx->adts, 7) != 7 || Bwrite(out, p->data, p->sz) != p->sz)			goto err;	}	ctx->frid++; 	return 0;err:	werrstr("aacpacket: adts: %r");	return -1;}