Hi Martin,
Consider the following flow graph.
File Source ------->Throttle --------> Packet Encoder -------> Packet Decoder --------->File Sink 2
\
\---------------> File Sink 1
If the File Source loads a small-size image (around 50 kB), then the Packet Decoder works properly and File Sink 2 can open the image. However if the File Source load a bigger image or video (9 MB, for example), then the File Sink 2 achieve only more than 1 MB, and it can only display a part of the image/video. This surprised me.
Then I added a File Sink right after the Packet Encoder (it's called File Sink 1) to see what happened after the Packet Encoder. If I let the Sample Rate = 32k, then the File Sink 1 receives more than 9 MB, but the File Sink 2 still receive more than 1 MB. If I let the Sample Rate be faster, 1M or 4M, then both the File Sink 1 and File Sink 2 only get more than 1MB.
I wonder if something related to CPU got out of ability with high Sample Rate or Packet Encoder - Packet Decoder
Best Regards,
V-L
Van-Ly Nguyen,
Signals and Systems of Laboratory - SSL
Faculty of Electronics and Telecommunications - FET
University of Engineering and Technology - UET
Vietnam National University, Hanoi - VNU
Tel: (+84) 978 819 406
On Wed, Jul 30, 2014 at 9:19 PM, Martin Braun <martin.braun@ettus.com> wrote:
On 07/30/2014 04:14 PM, Nguyễn Văn Lý wrote:> I found a note in documentation of the *Packet Encoder *block** where it
> Thank you Tom,
>
> declares that the *Packet Encoder* is for use with the gnuradio
> modulator blocks: GMSK, DPSK, QAM. I don't know why only these modulatorThese should also work (they are basically subsets of QAM), but *you*
> blocks are supported, but not some popular things like BPSK or QPSK.
> Another thing is that my task requires the use of OFDM.
have to make sure the absolute phase is correct *before* going into the
packet decoder.
> *File Source* block (text, image, or video ...), and the same question
> Suppose now I have a simple flow graph as below:
> File Source -------> Packet Encoder -------> Packet Decoder --------->
> File Sink
> I wonder what types of file can be loaded and processed properly in the
> for the *File Sink* block :-)
Any file. The packet blocks really don't care about the contents.
> Can anyone tell me what do *Packet Encoder* and *Packet Decoder*
M
>
> Thank you so much
> Van-Ly
>
>
> Van-Ly Nguyen,
> Signals and Systems of Laboratory - SSL
> Faculty of Electronics and Telecommunications - FET
> University of Engineering and Technology - UET
> Vietnam National University, Hanoi - VNU
>
> Tel: (+84) 978 819 406
>
>
>
> On Wed, Jul 30, 2014 at 8:24 PM, Tom Rondeau <tom@trondeau.com
> blocks do? and it would be great if you can give me some example> _______________________________________________
> :-)
> Thanks in advance
>
> Van-Ly
>
>
> These are very simple example blocks to show you how to packetize
> data. Packet bytes go in, they get wrapped into a packet of a given
> payload length with a header, access code, and preamble. The header
> is just a 2x repetition of the payload length (16 bits for each
> field). Leaving the preamble and access code blank just chooses the
> defaults.
>
> The decoder just looks for the access code with the number of
> available bits wrong. When it's found, it reads the header to get
> the payload length, extracts the payload, and outputs the payload.
>
> Hope this helps.
>
> Tom
>
>
>
>
>
> Discuss-gnuradio mailing list
> Discuss-gnuradio@gnu.org
> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
>
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