[libdvbpsi-devel] CAT decoding - bug

[Angelo Schiavone]

OK, I will test all of them and send all needed patches.


2013/1/23 Jean-Paul Saman <jpsaman at videolan.org>

> Angelo,
>
> Again thanks for finding this bug. I checked ITU-T Rec H.222.0 and you are
> correct.
> At this point p_section->payload_start points at the beginning of the
> descriptors for this PSI section.
>
> And adding 5 to the payload start at this point is plain wrong. I would
> not be surprised if more PSI sections
> suffer from the same type of bug. Could you please sent a git-patch for
> each one you come across in your testing?
>
> On Tue, Jan 22, 2013 at 4:11 PM, Angelo Schiavone <
> angelo.schiavone at gmail.com> wrote:
>
>> Hi all,
>> CAT decode function doesn't work very well in libpsisi 1.0.0, in fact
>> it may skip the last descriptor of the cat descriptor loop, according to
>> its length.
>> the problem is that red highlighted +5 which is not necessary.
>>
>>
>> void dvbpsi_cat_sections_decode(dvbpsi_cat_t* p_cat, dvbpsi_psi_section_t* p_section)
>>
>> {
>>
>>     uint8_t* p_byte;
>>
>>     while (p_section)
>>
>>     {
>>
>>         /* CAT descriptors */
>>
>>         p_byte = p_section->p_payload_start;
>>
>>         while (p_byte +5 <= p_section->p_payload_end)
>>
>>         {
>>
>>             uint8_t i_tag = p_byte[0];
>>
>>             uint8_t i_length = p_byte[1];
>>
>>             if (i_length + 2 <= p_section->p_payload_end - p_byte)
>>
>>                 dvbpsi_cat_descriptor_add(p_cat, i_tag, i_length, p_byte + 2);
>>
>>             p_byte += 2 + i_length;
>>
>>         }
>>
>>         p_section = p_section->p_next;
>>
>>     }
>>
>> }
>>
>>
>> _______________________________________________
>> libdvbpsi-devel mailing list
>> libdvbpsi-devel at videolan.org
>> http://mailman.videolan.org/listinfo/libdvbpsi-devel
>>
>>
> Kind regards,
>
> Jean-Paul Saman
>
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