Recover H264 encoded ts segments that dont have PPS/SPS

[Nicolas Dufresne]

Le mer. 3 mai 2023, 21 h 15, Guru Govindan <gurunathan.govindan at gmail.com>
a écrit :

> Hi Nicolas,
> Thanks for your response, I figured out a way to extract the h264 header
> by making another connection to the camera and extracting data from the
> first stream. I used help from here
> https://stackoverflow.com/questions/24884827/possible-locations-for-sequence-picture-parameter-sets-for-h-264-stream/24890903#24890903
>
> I also verified that the extracted header is valid by running `ffmpeg -i
> header1.h264 -an -c:v copy -bsf:v trace_headers -f null` and verified that
> it is a valid h264 file and contains SPS and PPS values.
>
> However when I cat the recovered header and copy the truncated file, it
> says it is not a valid file.
>
> Any ideas? Should it be inserted before every keyframe and not just in
> front of the file?
>


You only need it once, unless you had dynamic resolution change (which
never happen with security cam). My guess would be the stream format (avec
vs byte-stream), you want byte stream for mpeg ts.


>
> On Wed, May 3, 2023 at 12:47 PM Nicolas Dufresne <nicolas at ndufresne.ca>
> wrote:
>
>> Le mercredi 03 mai 2023 à 10:22 -0700, Guru Govindan via gstreamer-devel
>> a écrit :
>>
>> Hi There,
>> I am having an issue where a lot of video footage from a security camera
>> was recorded without the sprop-parameters-set (SPS/PPS).
>>
>> I am unable to play or transcode these ts files as it does not have
>> SPS/PPS values.
>>
>> I tried the following by sending the h264parse the stream format but that
>> failed
>>
>>
>> The only way to recover is to find the origin SPS/PPS, note, this is
>> static on most cameras. The sprop-parameters contains it, just it may need
>> to be transformed. Then something like this may work, but never tried`
>>
>> gst-launch-1.0 \
>>   filesrc location=truncated.ts ! tsdemux ! filesink
>> location=truncated.h264
>> cat recovered-header.h264 > fixed.h264
>> cat truncated.h264 >> fixed.h264
>> gst-launch-1.0 \
>>   filesrc location=fixed.h264 ! h264parse ! mpegtsmux ! filesink
>> location=fixed.ts
>>
>> This is video only though, totally untested.
>>
>> Nicolas
>>
>>
>> ```
>> gst-launch-1.0 -v filesrc location=2.ts ! tsparse ! tsdemux name=demux
>> demux. ! queue ! h264parse ! video/x-h264,stream-format=avc,alignment=au !
>> decodebin ! videoconvert ! vaapih264enc ! h264parse ! mpegtsmux
>> alignment=-1 ! filesink location=output.ts
>> ```
>> failed with /
>> GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:sink: caps =
>> video/x-h264, stream-format=(string)byte-stream
>> ERROR: from element /GstPipeline:pipeline0/GstH264Parse:h264parse0: No
>> valid frames found before end of stream
>>
>> I then tried to split it as per keyframes and then mux it.. like below
>> but that failed as well
>>
>> ```
>> gst-launch-1.0 -v filesrc location=2.ts ! tsdemux name=demux ! h264parse
>> ! splitmuxsink max-size-time=1000000000 location=segment%02d.ts mpegtsmux
>> name=mux ! filesink location=output.ts demux.video_0 ! queue ! mux.
>> ```
>> failed with h264parse0: No valid frames found before end of stream
>>
>> Since it could not find EOS.. I thoiught of sending the entire manifest..
>> but that didnt work as well
>>
>> ```
>> gst-launch-1.0 -v filesrc location="<manifest uri>" ! hlsdemux !
>> h264parse ! video/x-h264,stream-format='(string)avc,alignment=(string)au' !
>> mpegtsmux ! h264parse config-interval=-1 ! mpegtsmux ! filesink
>> location=output.ts
>> ```
>>
>> Just like how we can add config-interval to a rtp stream, is there a way
>> to add it to a ts segment?
>>
>> Best Regards,
>> Guru
>>
>>
>>
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