Messages in this thread | | | Date | Wed, 24 Nov 2004 23:16:33 +0100 (CET) | Subject | Re: Re: Is controlling DVD speeds via SET_STREAMING supported? | From | "Thomas Fritzsche" <> |
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Hi David,
I had the same problem with my DVD+-RW NEC-ND 3500 (NEC-support told me that they didn't support linux :-( ). After googling I couldn't find an answer. Because I didn't know anything about ide-cd (yesterday ;-)) I read in this spec about the SET STREAMING command: ftp://ftp.avc-pioneer.com/Mtfuji_4/Spec/Fuji4r10.pdf If you also read the newer Specs (Mtfuji_5) then you'll find out that the "SET CD SPEED" command is "only applicable to CD-R/RW logical units". It looks like older DVD-Drives also support this command, but newer do not support this for DVD+-R. But there is also the SET STREAMING command as Jens Axboe described on this list. Not all devices support this feature but my NEC-CD 3500 does (as I found out ;-) / my Teac-CD-RW does not)
I wrote a little programm to test this SET STREAMING command (quick & dirty). In my opinion it would make sence to also enhance the kernel function cdrom_select_speed (linux/drivers/ide/ide-cd.c), so that this function works also for "newer" DVD-drives. (!first check for the Realtime-Streaming-Feature and then use the right command to set the speed). Because DVD+-RW Drives will be faster (AND LOUDER!!) very soon it would be nice to have this in the kernel.
Thanks and regards, Thomas Fritzsche
PS.: I'm not subscribed to LKML please CC me If you would like to discuss this issue.
----------------------------------------- #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <string.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/cdrom.h>
/* * speed - use SET STREAMING command to set the speed of DVD-drives * * * Copyright (c) 2004 Thomas Fritzsche <tf@noto.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */
void dump_sense(unsigned char *cdb, struct request_sense *sense) { int i;
printf("Command failed: ");
for (i=0; i<12; i++) printf("%02x ", cdb[i]);
if (sense) { printf(" - sense: %02x.%02x.%02x\n", sense->sense_key, sense->asc, sense->ascq); } else { printf(", no sense\n"); } }
int main(int argc, char *argv[]) { int fd = open("/dev/hdc", O_RDONLY | O_NONBLOCK); int c; int speed = 0; unsigned char buffer[28];
struct cdrom_generic_command cgc; struct request_sense sense; extern char * optarg;
while((c=getopt(argc,argv,"x:"))!=EOF) { switch(c) { case 'x': speed = atoi(optarg); break; default: printf("Usage: speed -x <speed>"); exit(-1); } }
memset(&cgc, 0, sizeof(cgc)); memset(&sense, 0, sizeof(sense)); memset(&buffer, 0, sizeof(buffer));
/* SET STREAMING command */ cgc.cmd[0] = 0xb6; /* 28 byte parameter list length */ cgc.cmd[10] = 28;
cgc.sense = &sense; cgc.buffer = buffer; cgc.buflen = sizeof(buffer); cgc.data_direction = CGC_DATA_WRITE;
buffer[8] = 0xff; buffer[9] = 0xff; buffer[10] = 0xff; buffer[11] = 0xff;
buffer[15] = 177*speed; buffer[18] = 0x03; buffer[19] = 0xE8;
buffer[23] = 177*speed; buffer[26] = 0x03; buffer[27] = 0xE8;
if (ioctl(fd, CDROM_SEND_PACKET, &cgc) == 0) { printf("OK\n"); return 0; } else { printf("error!\n"); dump_sense(cgc.cmd, cgc.sense); return -1; } }
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---------------------------------------------------------- Date Sun, 21 Nov 2004 00:50:32 +0100 From David Härdeman <> Subject Re: Is controlling DVD speeds via SET_STREAMING supported?
On Sat, Nov 20, 2004 at 09:19:45PM +0100, Jens Axboe wrote: >On Sat, Nov 20 2004, David Härdeman wrote: >> So, my question is, is this implemented in the kernel and are there any >> userspace tools to set the playback speed? > >I don't know of any, but it is trival to write using SG_IO (or just >CDROM_SEND_PACKET for this simple use, since only a trivial amount of >data involved). If you are not sure how to do it, let me know and I can >easily write one in minutes.
If you could write up a quick-n-dirty tool, it would be great! Based on that I could hopefully write a patch later for one of the common tools (eg. hdparm or setcd).
Re¸ David
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