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Topics - GEFORCEXTREME

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H.264/AVC / Regarding image raw data output of x264_encoder_encode()

« on: March 29, 2011, 11:04:00 PM »

/* x264_encoder_encode:
* encode one picture.
* *pi_nal is the number of NAL units outputted in pp_nal.
* returns negative on error, zero if no NAL units returned.
* the payloads of all output NALs are guaranteed to be sequential in memory. */
int x264_encoder_encode( x264_t *, x264_nal_t **pp_nal, int *pi_nal, x264_picture_t *pic_in, x264_picture_t *pic_out );

If I were to draw the frame after calling x264_encoder_encode above (using raw data from pic_out->img), what type of image do I get? I tried it, but what I got is some low quality picture.

I don't know if this has to do with the x264 params set incorrectly/badly or are the pictures just delta pictures?
For example, in a

1 2 3 4 5
IDR P P P P

sequence, picture 2 drawn using the above method, is it the actual complete output of the frame or is it just "predicted and not motion estimated-compensated picture"?

Video Containers / MPEG2 TS and or MP4 container library I can use to carry x264 NALUs?

« on: March 28, 2011, 07:08:24 AM »

Referring to topic, is there any MPEG2 TS and or MP4 container library I can use to carry x264 NALUs?

Can we use ffmpeg libavformat for this? I tried to do this by learning from output-example.c from ffmpeg source. I can produce a video, but the video just doesn't play.

Back to topic, is there other library for this?

H.264/AVC / Any container/protocol libary to carry x264 data?

« on: March 27, 2011, 05:45:52 PM »

Ok, here is my dilemma, I need to use libx264 directly because I'm playing with interactive/adaptive transcoding features.

I've just learnt how to encode a frame using libx264, but that's it, I don't know what to do with the outputed NALUs.

I'm thinking of using ffmpeg libavformat libary to do container/protocol work, but can I? As of now, I'm using ffmpeg to decode and x264 to encode. But the output part is still big headache. Please help, thanks in advance!

H.264/AVC / Regarding x264_encoder_headers() in libx264

« on: March 21, 2011, 11:12:14 PM »

What does this do? According to x264.h,

/* x264_encoder_headers:
* return the SPS and PPS that will be used for the whole stream.
* *pi_nal is the number of NAL units outputted in pp_nal.
* returns negative on error.
* the payloads of all output NALs are guaranteed to be sequential in memory. */
int x264_encoder_headers( x264_t *, x264_nal_t **pp_nal, int *pi_nal );

The function is very much of the same structure as x264_encoder_encode() which encodes a single frame. The function return some amount of NALUs. How do I sent this over using RTP transport protocol? These NALUs, do I send them once for the whole video session?

If I want to send these (SPS, PPS) NALUs and VCL NALUs, is there a certain way I do this? Or do I just pack them into and set appropriate UDP/RTP headers and then send them over? I've read RFC3984: RTP Payload Format for H.264 Video, but I still can't understand how x264 video data are transferred. Someone please help.

H.264/AVC / Need help on x264_encoder_intra_refresh & x264_encoder_invalidate_reference

« on: February 21, 2011, 09:54:46 PM »

Hi guys,

I'm using VLC to stream H.264 videos encapsulated in MPEG2-TS. I would like to try out incorporating x264_encoder_intra_refresh() in VLC.
Assuming I have a feedback channel, everytime if the client senses packet loss, it sends a signal to server VLC which then do x264_encoder_intra_refresh. Is this the right way to do it?

How about x264_encoder_invalidate_reference()? From the x264 header it seems I need to know the pts. How do I know what/which pts of the reference frames to invalidate? Thanks.