[FFmpeg-devel] [PATCH] avcodec/alsdec: implement floating point decoding

[Umair Khan]

On Tue, Jul 19, 2016 at 11:17 PM, Umair Khan <omerjerk at gmail.com> wrote:
>
> Updated patch.
>
> On Tue, Jul 19, 2016 at 8:19 PM, Thilo Borgmann <thilo.borgmann at mail.de> wrote:
> > Am 19.07.16 um 15:42 schrieb Umair Khan:
> >> On Tue, Jul 19, 2016 at 5:20 PM, Thilo Borgmann <thilo.borgmann at mail.de> wrote:
> >>> Am 19.07.16 um 09:22 schrieb Umair Khan:
> >>>> On Tue, Jul 19, 2016 at 12:29 PM, Paul B Mahol <onemda at gmail.com> wrote:
> >>>>>
> >>>>> On 7/19/16, Umair Khan <omerjerk at gmail.com> wrote:
> >>>>>> On Tue, Jul 19, 2016 at 3:08 AM, Michael Niedermayer
> >>>>>> <michael at niedermayer.cc> wrote:
> >>>>>>> On Mon, Jul 18, 2016 at 11:42:48PM +0530, Umair Khan wrote:
> >>>>>>>> On Sun, Jul 17, 2016 at 3:38 PM, Michael Niedermayer
> >>>>>>>> <michael at niedermayer.cc> wrote:
> >>>>>>>>> On Sun, Jul 17, 2016 at 11:54:49AM +0200, Michael Niedermayer wrote:
> >>>>>>>>>> On Sun, Jul 17, 2016 at 09:00:48AM +0530, Umair Khan wrote:
> >>>>>>>>>>> Hi,
> >>>>>>>>>>>
> >>>>>>>>>>> On Sun, Jul 17, 2016 at 12:25 AM, Thilo Borgmann
> >>>>>>>>>>> <thilo.borgmann at mail.de> wrote:
> >>>>>>>>>>>> Hi,
> >>>>>>>>>>>>
> >>>>>>>>>>>>> From 70e65b26cc3f84c9c664c30808b43a5e1cf16eaa Mon Sep 17 00:00:00
> >>>>>>>>>>>>> 2001
> >>>>>>>>>>>>> From: Umair Khan <omerjerk at gmail.com>
> >>>>>>>>>>>>> Date: Sat, 16 Jul 2016 23:52:39 +0530
> >>>>>>>>>>>>> Subject: [PATCH 1/1] avcodec/alsdec: implement floating point
> >>>>>>>>>>>>> decoding
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> It conforms to RM22 version of the reference codec.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Signed-off-by: Umair Khan <omerjerk at gmail.com>
> >>>>>>>>>>>>> ---
> >>>>>>>>>>>>>  libavcodec/Makefile           |   2 +-
> >>>>>>>>>>>>>  libavcodec/alsdec.c           | 284
> >>>>>>>>>>>>> +++++++++++++++++++++++++++++++++++++++++-
> >>>>>>>>>>>>>  libavcodec/mlz.c              | 171 +++++++++++++++++++++++++
> >>>>>>>>>>>>>  libavcodec/mlz.h              |  69 ++++++++++
> >>>>>>>>>>>>>  libavutil/softfloat_ieee754.h | 115 +++++++++++++++++
> >>>>>>>>>>>>>  5 files changed, 638 insertions(+), 3 deletions(-)
> >>>>>>>>>>>>>  create mode 100644 libavcodec/mlz.c
> >>>>>>>>>>>>>  create mode 100644 libavcodec/mlz.h
> >>>>>>>>>>>>>  create mode 100644 libavutil/softfloat_ieee754.h
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> >>>>>>>>>>>>> index abef19e..a03adf5 100644
> >>>>>>>>>>>>> --- a/libavcodec/Makefile
> >>>>>>>>>>>>> +++ b/libavcodec/Makefile
> >>>>>>>>>>>>> @@ -163,7 +163,7 @@ OBJS-$(CONFIG_ALAC_DECODER)            +=
> >>>>>>>>>>>>> alac.o alac_data.o alacdsp.o
> >>>>>>>>>>>>>  OBJS-$(CONFIG_ALAC_ENCODER)            += alacenc.o alac_data.o
> >>>>>>>>>>>>>  OBJS-$(CONFIG_ALIAS_PIX_DECODER)       += aliaspixdec.o
> >>>>>>>>>>>>>  OBJS-$(CONFIG_ALIAS_PIX_ENCODER)       += aliaspixenc.o
> >>>>>>>>>>>>> -OBJS-$(CONFIG_ALS_DECODER)             += alsdec.o bgmc.o
> >>>>>>>>>>>>> mpeg4audio.o
> >>>>>>>>>>>>> +OBJS-$(CONFIG_ALS_DECODER)             += alsdec.o bgmc.o mlz.o
> >>>>>>>>>>>>> mpeg4audio.o
> >>>>>>>>>>>>>  OBJS-$(CONFIG_AMRNB_DECODER)           += amrnbdec.o
> >>>>>>>>>>>>> celp_filters.o   \
> >>>>>>>>>>>>>                                            celp_math.o
> >>>>>>>>>>>>> acelp_filters.o \
> >>>>>>>>>>>>>                                            acelp_vectors.o
> >>>>>>>>>>>>>      \
> >>>>>>>>>>>>> diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
> >>>>>>>>>>>>> index a7e58a2..c710fc3 100644
> >>>>>>>>>>>>> --- a/libavcodec/alsdec.c
> >>>>>>>>>>>>> +++ b/libavcodec/alsdec.c
> >>>>>>>>>>>>> @@ -35,8 +35,11 @@
> >>>>>>>>>>>>>  [...]
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> +/** multiply two softfloats and handle the rounding off
> >>>>>>>>>>>>> + */
> >>>>>>>>>>>>> +static SoftFloat_IEEE754 multiply(SoftFloat_IEEE754 a,
> >>>>>>>>>>>>> SoftFloat_IEEE754 b) {
> >>>>>>>>>>>>> [...]
> >>>>>>>>>>>>
> >>>>>>>>>>>> Why is this in alsdec.c?
> >>>>>>>>>>>
> >>>>>>>>>>> This is not the actual IEEE 754 multiplication. It is as is
> >>>>>>>>>>> mentioned
> >>>>>>>>>>> in the reference spec.
> >>>>>>>>>>> The typical one for 754 floats, I've implemented here separately -
> >>>>>>>>>>> https://github.com/omerjerk/FFmpeg/commit/d6cd4bf66b9da46dd87580d7d974ce44abdcfba2#diff-4dd4b2d8d523f336fbefa96e9252187cR93
> >>>>>>>>>>>
> >>>>>>>>>>>> [...]
> >>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/libavcodec/mlz.c b/libavcodec/mlz.c
> >>>>>>>>>>>>> new file mode 100644
> >>>>>>>>>>>>> index 0000000..cb2ed6a
> >>>>>>>>>>>>> --- /dev/null
> >>>>>>>>>>>>> +++ b/libavcodec/mlz.c
> >>>>>>>>>>>>> [...]
> >>>>>>>>>>>>
> >>>>>>>>>>>>> +static int input_code(GetBitContext* gb, int len) {
> >>>>>>>>>>>>> +    int tmp_code = 0;
> >>>>>>>>>>>>> +    int i;
> >>>>>>>>>>>>> +    for (i = 0; i < len; ++i) {
> >>>>>>>>>>>>> +        tmp_code += get_bits1(gb) << i;
> >>>                              |=
> >>> should be better.
> >>>
> >>>>>>>>>>>>> +    }
> >>>>>>>>>>>>> +    return tmp_code;
> >>>>>>>>>>>>> +}
> >>>
> >>> Also, you could revert it byte-wise using ff_revert[]... if len is often bigger
> >>> than 8 that might be worth it.
> >>
> >> I didn't get you.
> >
> > tmp_code |= get_bits1(gb) << i;
> >
> >
> >> I tried logging that variable and len is always greater than 8. So
> >> what should we go with?
> >> It was 9 or 10 for the file I ran. And going with the logic of lzw, it
> >> will hardly be greater than 11 ever.
> >
> > I think it would not benefit enough from ff_reverse then. Keep the loop.

I'm really sorry for top posting. But anything else with the patch left?

-Umair