Re: [Discuss-gnuradio] Question about tagged_stream_block

[Martin Braun]

If you change the size of a tagged stream without changing the tag,
you're producing invalid data. (This may change on 3.8, we haven't
finalized any decisions yet).

However, how are you dropping samples in software? Or are you dropping
them in hardware, in which case why are you not tagging the streams
correctly?

M

On 06/22/2016 12:10 AM, bob wole wrote:
> Thanks Martin,
> 
> I know the packet size a priori but samples may drop due to overflows
> while flowgraph is running and could result in different packet size. Is
> there a way to solve this issue while using tagged_stream_block?
> 
> --
> Bob
> 
> 
>     It'll crash. If you know your packet size a priori, you can tell the
>     scheduler to only provide multiples of a 1000 samples.
> 
>     Cheers,
>     M
> 
>     On 06/20/2016 07:17 AM, bob wole wrote:
>     > Hi,
>     > My  flowgraph contains a tagged_stream_block, B, and it has a
>     > length_tag_key, say "pkt_len". Each packet has a length of 1000
>     samples.
>     > The upstream block (A-->B) tags first sample with key "pkt_len" and
>     > value 1000 and then the upstream block tags sample number 901 with key
>     > "pkt_len" and value 1000 instead of tagging sample number 1001. This
>     > could happen in case of overflow and I know using receive tags
>     that 100
>     > samples has been lost. So, samples from 901 to 1900 contains a new
>     > packet. Will the flowgraph work or will it crash?
>     >
>     > I want to write a block that processes exactly only 1000 samples, one
>     > packet, in a call to work. And the packets start from a specific time
>     > for example when the rx_time of the sample is mid of any second.
>     >
>     >
>     > --
>     > Bob
> 
> 
> 
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