[linux-dvb] mplex and mpegtools 2gb limit

[Chris Pitchford <nova-t@intrepid.cx>]

Hi all,

Ive upgraded to 2.4.20-rc3 and CVS dated 23rd Nov and my Nova-T card has
been working a treat! Since I was out and about last night I cron'd up
dvbstream to record "Analyse This" from Channel 5 here in the UK and it
worked perfectly.. which beat ALL my previous attempts.. usually I get
serious block errors (according to dvbtune -m) and no more than 5 minutes
uncorrupted video.. It all seems fine now.. which is good! Just hoping its
not due to the weather ;)

Anyway,

Now I have a 4.3 GB TS_Stream dump on my machine, I was kind of hoping I
could convert it into a "mpg" file so I could edit out the adverts and
watch it normally.

Ive been doing this for ages with various programs but all have been no
longer than 30 minutes (1.1gig-ish) using mplex bundled in the CVS tree.


Now, I'm finding that I cannot use mplex with files greater than 2 GBytes.

<snip>
# mplex  -t MPEG2 -i TS_STREAM -o AnalyseThis.mpg  DVB-9-20021127-2059.36+2h10m.ts

Reading from DVB-9-20021127-2059.36+2h10m.ts
Output File is: AnalyseThis.mpg
Setting up for MPEG2 mux

Opening tmp_as.mp2 for audio demux
Opening tmp_vs.m2v for video demux
TS demux with apid: 0  vpid: 0
Videostream: ASPECT: 16:9  Size = 720x576  FRate: 25 fps  BRate: 4.45
Mbit/s
vpts : 6135.087156s
Audiostream: Layer: 2  BRate: 256 kb/s  Freq: 48.0 kHz
apts : 6134.768433s
					<!!!!LONG PAUSE!!!!>
VPTS - APTS = 318ms
Unable to open file tmp_vs.m2v for reading.
</snip>

During the long pause it does indeed make the two temporary files, as per
usual, but its after they have been created it all goes wrong.. more
investigation revealed....


<snip>
# ts2es DVB-9-20021127-2059.36+2h10m.ts 1 > vid
ts2es
				<!!!!LONG PAUSE Then HANG!!!!>
^C
# ts2es DVB-9-20021127-2059.36+2h10m.ts 2 > aud
ts2es
                                <!!!!LONG PAUSE Then HANG!!!!>
^C
</snip>

when using ts2es, the operation does indeed seem to finish BUT it hangs at
the end, rather than exiting. Here is the end of the "strace" of the above
processes:

read(3, "", 1880)                       = 0
read(3, "", 1880)                       = 0
read(3, "", 1880)                       = 0
[repeats forever]
read(3,  <unfinished ...>

Anyway, hitting CTRL-C when the file sizes stop growing seems to be
enough..

Now I have two files "vid" and "aud".. So I thought I'd try to use mplex
to join these files: (note vid is 4.5gig)
<snip>
# mplex -t MPEG2 -i ES_STREAM -o AnalyseThis.mpg aud vid
Output File is: AnalyseThis.mpg
Setting up for MPEG2 mux


VPTS - APTS = 0ms
Unable to open file vid for reading.
#
</snip>
Here's the strace output that seems to suggest what might be preventing
mplex from getting past this point:

open("vid", O_RDONLY|0x8000)            = 3
fstat64(0x3, 0xbffff09c)                = 0
old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40015000
fstat64(0x3, 0xbffff17c)                = 0
_llseek(3, 4533768192, [4533768192], SEEK_SET) = 0
read(3, "\262\303J\0\264\345\213u\217\220$\232\10\177\367\304 \260"..., 1997) = 1997
close(3)                                = 0
munmap(0x40015000, 4096)                = 0
open("vid", O_RDONLY)                   = -1 EFBIG (File too large)
write(2, "Unable to open file vid for read"..., 37Unable to open file vid for reading.

It seems that vid is being opened twice, the first time with large file
support, though this is only for a see and read operation.. the second
time without largefile support hence the "EFBIG (File too large)"

I like the obviously incorrect error message:
	"Unable to open file vid for read"
since that is exactly what it did prior to the attempting to open the file
a second time!?


Basically, and please excuse this long email, does anyone know if there is
a plan for 2GB+ file support for mplex, or alternatively, another tool
that will convert either two ES_Streams or a TS_Stream into a "mpeg" file
of the format mplex outputs?

a 45 minute limitation in recording is not really very helpful. Is anyone
out there having any luck with large TS_stream files?

Any help would be greatly appreciated.. Now I have a stable recording
platform I'd love to be able to use cron to record my fav TV shows since I
work some really inconvienient hours and I'm never home to watch them!

Thanks

Chris




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