Update audio code to use size_t more correctly,

Update audio code to use size_t more correctly,
webrtc/modules/audio_coding/codecs/ilbc/ portion.

This is a piece of https://codereview.webrtc.org/1230503003 , split out to a
separate change to make reviewing easier.

BUG=chromium:81439
TEST=none

[Peter Kasting, 2015-07-23 19:17:03]

pkasting@chromium.org changed reviewers:
+ kwiberg@webrtc.org

[Peter Kasting, 2015-07-23 19:17:04]

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc:28: const size_t
AudioEncoderIlbc::kMaxSamplesPerPacket;
Changing the type of this from int to size_t means some compilers will complain
if it doesn't have an explicit definition in addition to the declaration. 
constexpr might be able to address this if only it worked in MSVC.

[Peter Kasting, 2015-07-27 23:41:54]

pkasting@chromium.org changed reviewers:
+ minyue@webrtc.org, turaj@webrtc.org
- kwiberg@webrtc.org

[Peter Kasting, 2015-07-27 23:42:34]

pkasting@chromium.org changed reviewers:
- minyue@webrtc.org

[Peter Kasting, 2015-07-27 23:43:17]

Changing reviewer to turaj in hopes of finding someone who is not on vacation to
review.

[Peter Kasting, 2015-08-07 22:01:13]

pkasting@chromium.org changed reviewers:
+ henrik.lundin@webrtc.org, tina.legrand@webrtc.org
- turaj@webrtc.org

[Peter Kasting, 2015-08-07 22:01:35]

Changing reviewers again; Tina or Henrik, could one of you review?

[kwiberg-webrtc, 2015-08-11 09:33:20]

kwiberg@webrtc.org changed reviewers:
+ kwiberg@webrtc.org

[kwiberg-webrtc, 2015-08-11 09:33:21]

Looks mostly good, but I have some concerns.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc:23: const size_t
kSampleRateHz = 8000;
It seems wrong to use size_t for sample rates. It's not an array size or
anything like that, it's a physical quantity. Array sizes are often derived from
it, but better to convert to size_t at that point.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc:28: const size_t
AudioEncoderIlbc::kMaxSamplesPerPacket;
On 2015/07/23 19:17:04, Peter Kasting wrote:
> Changing the type of this from int to size_t means some compilers will
complain
> if it doesn't have an explicit definition in addition to the declaration. 
> constexpr might be able to address this if only it worked in MSVC.

Acknowledged.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/augmented_cb_corr.c (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/augmented_cb_corr.c:49: ilow =
lagcount-4;
Fix spacing while you touch the line?

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c:121: size_t Nfor =
iLBCdec_inst->nsub - iLBC_encbits->startIdx - 1;
I presume this can't be negative?

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c:159: size_t Nback =
iLBC_encbits->startIdx - 1;
I presume this can't be negative?

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/my_corr.h (left):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/my_corr.h:32: const int16_t* seq2, /*
(i) second sequence */
Why is seq2 no longer const?

[Peter Kasting, 2015-08-14 00:56:09]

PTAL.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc:23: const size_t
kSampleRateHz = 8000;
On 2015/08/11 09:33:21, kwiberg-webrtc wrote:
> It seems wrong to use size_t for sample rates. It's not an array size or
> anything like that, it's a physical quantity. Array sizes are often derived
from
> it, but better to convert to size_t at that point.

I agree, I'm not sure why I changed this.  Fixed.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/augmented_cb_corr.c (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/augmented_cb_corr.c:49: ilow =
lagcount-4;
On 2015/08/11 09:33:21, kwiberg-webrtc wrote:
> Fix spacing while you touch the line?

Done.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c (right):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c:121: size_t Nfor =
iLBCdec_inst->nsub - iLBC_encbits->startIdx - 1;
On 2015/08/11 09:33:21, kwiberg-webrtc wrote:
> I presume this can't be negative?

Yes, due to the conditional on line 112.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/decode_residual.c:159: size_t Nback =
iLBC_encbits->startIdx - 1;
On 2015/08/11 09:33:21, kwiberg-webrtc wrote:
> I presume this can't be negative?

Yes, due to the conditional on line 144.

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
File webrtc/modules/audio_coding/codecs/ilbc/my_corr.h (left):

https://codereview.webrtc.org/1230693002/diff/20001/webrtc/modules/audio_codi...
webrtc/modules/audio_coding/codecs/ilbc/my_corr.h:32: const int16_t* seq2, /*
(i) second sequence */
On 2015/08/11 09:33:21, kwiberg-webrtc wrote:
> Why is seq2 no longer const?

I don't know.  This must have been a typo.  Fixed.

[hlundin-webrtc, 2015-08-14 09:21:56]

Karl is taking this review. Removing myself from reviewers. Thanks for doing
this, Peter!

[tlegrand-webrtc, 2015-08-14 11:27:26]

On 2015/08/14 09:21:56, hlundin-webrtc wrote:
> Karl is taking this review. Removing myself from reviewers. Thanks for doing
> this, Peter!

Thanks for all the clean-up work Peter! Highly appreciated.
No need to wait for me to review, it's enough to get approval from Karl. Same
goes for the other open CLs where I'm one of the reviewers.
Let me know if you need my input on something specific.

[kwiberg-webrtc, 2015-08-17 10:33:53]

Thanks. lgtm

[hlundin-webrtc, 2015-08-17 10:49:02]

henrik.lundin@webrtc.org changed reviewers:
- henrik.lundin@webrtc.org