[FFmpeg-devel] [PATCH] avcodec/mlz: simplify

[Paul B Mahol]

On 7/2/17, Thilo Borgmann <thilo.borgmann at mail.de> wrote:
> Am 01.07.17 um 19:03 schrieb Paul B Mahol:
>> On 7/1/17, Thilo Borgmann <thilo.borgmann at mail.de> wrote:
>>> Am 01.07.17 um 14:42 schrieb Paul B Mahol:
>>>> On 7/1/17, Michael Niedermayer <michael at niedermayer.cc> wrote:
>>>>> On Sat, Jul 01, 2017 at 02:18:17PM +0200, Paul B Mahol wrote:
>>>>>> On 7/1/17, Michael Niedermayer <michael at niedermayer.cc> wrote:
>>>>>>> On Sat, Jul 01, 2017 at 12:05:52PM +0200, Paul B Mahol wrote:
>>>>>>>> Signed-off-by: Paul B Mahol <onemda at gmail.com>
>>>>>>>> ---
>>>>>>>>  libavcodec/mlz.c | 7 +------
>>>>>>>>  1 file changed, 1 insertion(+), 6 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/libavcodec/mlz.c b/libavcodec/mlz.c
>>>>>>>> index ebce796..715ea5c 100644
>>>>>>>> --- a/libavcodec/mlz.c
>>>>>>>> +++ b/libavcodec/mlz.c
>>>>>>>> @@ -112,12 +112,7 @@ static int decode_string(MLZ* mlz, unsigned
>>>>>>>> char
>>>>>>>> *buff, int string_code, int *fi
>>>>>>>>  }
>>>>>>>>
>>>>>>>>  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;
>>>>>>>> -    }
>>>>>>>> -    return tmp_code;
>>>>>>>> +    return get_bitsz(gb, len);
>>>>>>>
>>>>>>> have you tested this ? (seems not triggered in fate, i ve only found
>>>>>>> fuzzed samples that trigger this with len >= 1 quickly)
>>>>>>> isnt this the opposite endianness ?
>>>>>>
>>>>>> I created file with 22rev2 als encoder and decoding produce same hash,
>>>>>> before and after this patch.
>>>>>>
>>>>>> ALS uses big endian bit reader.
>>>>>
>>>>> ok, but please change the commit message then as the code before and
>>>>> afterwards dont read in the same endianness so this is not a
>>>>> simplification but a bugfix then
>>>>
>>>> Hmm, on second look you are probably right.
>>>> They changed to this in R23 version and I failed to create file that
>>>> triggers this path.
>>>> So I will not apply this mostly because R23 support needs more work.
>>>
>>> Do I understand correctly, this patch works with RM22 only and fails on
>>> RM23?
>>
>> Probably. I can not confirm because I failed to create sample with
>> path that triggers this code.
>
> Well it should get applied only if it could properly be tested for both
> endianness cases.

Yes, until then I will not apply this. As float code works fine with R22rev2.