#57 Consistent output for overlap audios.

[Mostafa Jabaroutimoghaddam]

Hi All,

I have two wave files that have a common audio about 5 seconds. The last 5 seconds of the first audio is the same as the first 5 seconds of the last. should'nt the output of the mp3 with the same setting be same for at least the frames after 500 ms?

Best Regards,
Mostafa

[Elio Blanca]

In practice, this is VERY hard to achieve.
On the first hand, MPEG audio Layer III allows for any frames to keep some room for data belonging to upcoming frames, in order to give them more bits (and more quality in the end). This is called 'bit reservoir' and this makes the frames from the beginning of your second file different from the last frames at the end of your first file, as the latter don't need to keep any room because they don't have any upcoming frames.
On the other hand, lame allows you to disable bit reservoir (and lose the benefit from an efficient compression) but even in this case, frames from the two files will differ as well, as they should be encoded feeding sample-exact data. Actually, the trailing frames from the first file also include the 'encoder padding' (a non-fixed small amount of samples at the very end) and the heading frames from your second file also include the 'encoder delay' (a non-fixed small amount of samples at the very beginning).

[Mostafa Jabaroutimoghaddam]

Hi All,

I have done this by some techniques and changed the LAME library to support
the multislice. I should know If I have permission to publish it or not.

Best Regards,
Mostafa

On Fri, Jun 26, 2020 at 5:07 PM Elio Blanca eblanca76@users.sourceforge.net
wrote:

In practice, this is VERY hard to achieve.
On the first hand, MPEG audio Layer III allows for any frames to keep some
room for data belonging to upcoming frames, in order to give them more bits
(and more quality in the end). This is called 'bit reservoir' and this
makes the frames from the beginning of your second file different from the
last frames at the end of your first file, as the latter don't need to keep
any room because they don't have any upcoming frames.
On the other hand, lame allows you to disable bit reservoir (and lose the
benefit from an efficient compression) but even in this case, frames from
the two files will differ as well, as they should be encoded feeding
sample-exact data. Actually, the trailing frames from the first file also
include the 'encoder padding' (a non-fixed small amount of samples at the
very end) and the heading frames from your second file also include the
'encoder delay' (a non-fixed small amount of samples at the very beginning).

---

• [support-requests:#57]
  https://sourceforge.net/p/lame/support-requests/57/ Consistent output for
  overlap audios.*

Status: open
Group:
Created: Sat May 16, 2020 11:06 AM UTC by Mostafa Jabaroutimoghaddam
Last Updated: Sat May 16, 2020 11:06 AM UTC
Owner: nobody

Hi All,

I have two wave files that have a common audio about 5 seconds. The last 5
seconds of the first audio is the same as the first 5 seconds of the last.
should'nt the output of the mp3 with the same setting be same for at least
the frames after 500 ms?

Best Regards,
Mostafa

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Best Regards,
MJM

[Mostafa Jabaroutimoghaddam]

The source code and modified lame to support multi-threaded wave to mp3
converted is as follows:
I hope you like it.
this the modified version of lame:
https://github.com/zavataafnan/mutlithreaded_lame

this the sample code using the modified version of lame:
https://github.com/zavataafnan/multithreaded_wav2mp3

Let me if you have any comments.
Best Regards,
Mostafa

On Fri, Jun 26, 2020 at 6:41 PM Mostafa Jabaroutimoghaddam zavataafnan@users.sourceforge.net wrote:

Hi All,

I have done this by some techniques and changed the LAME library to support
the multislice. I should know If I have permission to publish it or not.

Best Regards,
Mostafa

On Fri, Jun 26, 2020 at 5:07 PM Elio Blanca
eblanca76@users.sourceforge.net
wrote:

In practice, this is VERY hard to achieve.
On the first hand, MPEG audio Layer III allows for any frames to keep some
room for data belonging to upcoming frames, in order to give them more bits
(and more quality in the end). This is called 'bit reservoir' and this
makes the frames from the beginning of your second file different from the
last frames at the end of your first file, as the latter don't need to keep
any room because they don't have any upcoming frames.
On the other hand, lame allows you to disable bit reservoir (and lose the
benefit from an efficient compression) but even in this case, frames from
the two files will differ as well, as they should be encoded feeding
sample-exact data. Actually, the trailing frames from the first file also
include the 'encoder padding' (a non-fixed small amount of samples at the
very end) and the heading frames from your second file also include the
'encoder delay' (a non-fixed small amount of samples at the very
beginning).

---

• [support-requests:#57]
  https://sourceforge.net/p/lame/support-requests/57/
  https://sourceforge.net/p/lame/support-requests/57/ Consistent output
  for
  overlap audios.*

Status: open
Group:
Created: Sat May 16, 2020 11:06 AM UTC by Mostafa Jabaroutimoghaddam
Last Updated: Sat May 16, 2020 11:06 AM UTC
Owner: nobody

Hi All,

I have two wave files that have a common audio about 5 seconds. The last 5
seconds of the first audio is the same as the first 5 seconds of the last.
should'nt the output of the mp3 with the same setting be same for at least
the frames after 500 ms?

Best Regards,
Mostafa

---

Sent from sourceforge.net because you indicated interest in
https://sourceforge.net/p/lame/support-requests/57/

To unsubscribe from further messages, please visit
https://sourceforge.net/auth/subscriptions/

--
Best Regards,
MJM

---

• [support-requests:#57]
  https://sourceforge.net/p/lame/support-requests/57/ Consistent output for
  overlap audios.*

Status: open
Group:
Created: Sat May 16, 2020 11:06 AM UTC by Mostafa Jabaroutimoghaddam
Last Updated: Fri Jun 26, 2020 03:07 PM UTC
Owner: nobody

Hi All,

I have two wave files that have a common audio about 5 seconds. The last 5
seconds of the first audio is the same as the first 5 seconds of the last.
should'nt the output of the mp3 with the same setting be same for at least
the frames after 500 ms?

Best Regards,
Mostafa

---

Sent from sourceforge.net because you indicated interest in
https://sourceforge.net/p/lame/support-requests/57/

To unsubscribe from further messages, please visit
https://sourceforge.net/auth/subscriptions/

--
Best Regards,
MJM