Combining music or video files?

[John Salerno]

Before I try this and destroy my computer :) I just wanted to see if
this would even work at all. Is it possible to read a binary file such
as an mp3 or an avi, put its contents into a new file, then read another
such file and append its contents to this same new file as well, thereby
making, for example, a single long video instead of two smaller ones?

Thanks.

[Jason Scheirer]

On Jun 15, 7:53*pm, John Salerno <[e-mail]:

Before I try this and destroy my computer :) I just wanted to see if
this would even work at all. Is it possible to read a binary file such
as an mp3 or an avi, put its contents into a new file, then read another
such file and append its contents to this same new file as well, thereby
making, for example, a single long video instead of two smaller ones?

Thanks.

This works with basic mpeg videos, but pretty much nothing else.
You're going to need some video editing software.

[Dan Upton]

On Sun, Jun 15, 2008 at 11:55 PM, Jason Scheirer
<ja************@gmail.comwrote:

On Jun 15, 7:53 pm, John Salerno <[e-mail]:

>Before I try this and destroy my computer :) I just wanted to see if
this would even work at all. Is it possible to read a binary file such
as an mp3 or an avi, put its contents into a new file, then read another
such file and append its contents to this same new file as well, thereby
making, for example, a single long video instead of two smaller ones?

Thanks.

This works with basic mpeg videos, but pretty much nothing else.
You're going to need some video editing software.
--
http://mail.python.org/mailman/listinfo/python-list

I actually don't know what would happen if you concatenated even MP3s
with the ID3 tags that are stored at the end... I know with some DivX
files at least you could approximate this by running a separate
program on them that would recreate whatever index it needed. (At
least, you could recreate the index for files that cut off early, I
guess it could figure out what to do if it found a second index
halfway through the file.)

[Python.Arno]

On 16 jun 2008, at 05:55, Jason Scheirer wrote:

On Jun 15, 7:53 pm, John Salerno <[e-mail]:

>Before I try this and destroy my computer :) I just wanted to see if
this would even work at all. Is it possible to read a binary file
such
as an mp3 or an avi, put its contents into a new file, then read
another
such file and append its contents to this same new file as well,
thereby
making, for example, a single long video instead of two smaller ones?

Thanks.

This works with basic mpeg videos, but pretty much nothing else.
You're going to need some video editing software.

you can't just edit mpeg (including mp3)...
mpeg is a stream. it sets a "key" frame for the first frame
followed by motion vectors from the changes from that frame
until the next keyframe.
If you cut in the middle of the vectors the keyframe is lost
and the vector frames don;t make any sense anymore.

avi is not a video codec, it's a container like quicktime.
so it depends...

I come from a Mac background and use quicktime a lot.
there are some basic editing features that quicktime can do.
And Apple has a nice quicktime python module in OSX.
I bet there's something for windows too...

best thing to do is convert the video o a framesequence and
the audio to an uncompressed format like wav or aiff
then combine in quicktime or <something in windows>

cheers,
Arno

[John Salerno]

"Dennis Lee Bieber" <wl*****@ix.netcom.comwrote in message
news:1b******************************@earthlink.co m...

On Sun, 15 Jun 2008 22:53:19 -0400, John Salerno
<jo******@gmailNOSPAM.comdeclaimed the following in comp.lang.python:
Even the simplest format -WAV, which is normally uncompressed
audio samples, is wrapped in layers of informational packets.

snip other stuff!!!

Yikes! Then what I'm reading from your post (and others) is no, I can't do
it my way. ;) It *did* seem a little too easy, after all!

[Roger Heathcote]

John Salerno wrote:

"Dennis Lee Bieber" <wl*****@ix.netcom.comwrote in message
news:1b******************************@earthlink.co m...

>On Sun, 15 Jun 2008 22:53:19 -0400, John Salerno
<jo******@gmailNOSPAM.comdeclaimed the following in comp.lang.python:
Even the simplest format -WAV, which is normally uncompressed
audio samples, is wrapped in layers of informational packets.

snip other stuff!!!

Yikes! Then what I'm reading from your post (and others) is no, I can't do
it my way. ;) It *did* seem a little too easy, after all!

I can't speak for video (and I'd imagine it's a factor more difficult)
but it's really not that hard to concatenate audio in python. What you
need to do...

Import the right modules for the audio formats you want to read.
Decide on a master output format, say CD quality - PCM 16bit 44.1Khz Stereo.
Open a file for appending
Read through each of your source files loading them into memory
Get the sample rate and format
Run the sample data through a function to convert it to the master
output format*
Squirt it to disk

Finally take the resulting file, calculate a new header and munge the
two together. Voila :)
*I'm sure several modules have functions/methods for this but it
wouldn't be very hard to roll your own either.
Roger Heathcote

http://www.technicalbloke.com

[Paul Boddie]

On 16 Jun, 04:53, John Salerno <[e-mail]:

Before I try this and destroy my computer :) I just wanted to see if
this would even work at all. Is it possible to read a binary file such
as an mp3 or an avi, put its contents into a new file, then read another
such file and append its contents to this same new file as well, thereby
making, for example, a single long video instead of two smaller ones?

Probably not, as people have pointed out, but I imagine you could use
GStreamer and a few processing pipelines, as I pointed out in a
comment on the following article (for another task):

http://jessenoller.com/2008/05/06/la...ion-libraries/

This is probably as close as you can get to treating the files as if
they were simple things which can be concatenated.

Paul