[FFmpeg-devel] [PATCH] lavc/flacdec: Add frame CRC calculation

[Paul B Mahol]

On 2/17/13, James Almer <jamrial at gmail.com> wrote:
> On 17/02/13 11:00 AM, Michael Niedermayer wrote:
>> On Sun, Feb 17, 2013 at 12:09:29AM -0300, James Almer wrote:
>>>
>>> Afaik, dropping the frame or not on crc checks currently depends on the
>>> decoder and not the user.
>>
>> the user can change the options
>>
>> i think the check should be
>> if(err & (AV_EF_CRCCHECK|AV_EF_COMPLIANT))
>>
>> and we should think about loosing AV_EF_CRCCHECK from the default
>> flags
>
> What i meant is that currently, based on the value of err, most (or all)
> decoders with frame crc checking either check for data integrity and drop
> the frame if it's damaged, or don't check anything.
> The user can choose to enable or disable the check, but the frame being
> dropped or not if it's damaged is decided by the decoder (Returning < 0 or
> not).
>
> I'm not sure what's best as default, but i think we should add a flag or
> option to let the user choose to do a crc check without dropping the
> frame (Only showing a warning) aside from the current "check, warn and drop"
>
> behavior every decoder is using.

You chech crc if AV_EF_CRCCHECK is set.

You drop one if AV_EF_COMPLIANT (or some better flag) is also set.

>
> Regards.
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