Linux/DRA746: whether 264 decoder can get width and height from sps/pps

thank you sam. i got it but i still have some problems.
Refer Appendix D: Parse Header Support of the H264-Decoder-User-Guide.pdf
first client application needs to perform a XDM_SETPARAMS control call with dynamicParams->decodeHeader = XDM_PARSE_HEADER. Sequence of operations on the application side typically is as follows:
1. Decoder_Create
2. Control call (XDM_SETPARAMS) to configure decoder in parse
header mode
3. Process call to decoder which shall decode SPS+PPS
4. Control call (XDM_GETBUFINFO) to understand buffer
requirements
5. Allocate buffers of size exactly needed to decode this particular bit
stream
6. Control call (XDM_SETPARAMS) to configure decoder in normal
mode (dynamicParams->decodeHeader = XDM_DECODE_AU)
7. Process calls to decode frames

but i still cannot get width and height of the stream from step 4(XDM_GETBUFINFO control) , which are meaningful to application side.
only i can get minNumInBufs/minNumOutBufs/minInBufSize/minOutBufSize which are in struct XDM1_AlgBufInfo.

i hope 264 decoder can parse w/h from sps/pps if stream format is change(such as width/height/min output buffer count) and notify them to application side, so application re-create surface to display.

Hi Gao,
Status structure from where you get minNumInBufs etc also has elements outputWidth and outputHeight.
This should have the width and height of the stream. Can you check?

Ram

If outputWidth and outputHeight are not correct values with XDM_GETBUFINFO, try with XDM_GETSTATUS first

Hi Sam, it seems not work.

I taken the following steps:
1. setup dynamic param with XDM_PARSE_HEADER
2. allocate one input buffer(XDM2_BufDesc* ) to store sps/pps data and in args(VIDDEC3_InArgs*) , which is the same with normal decoding procedure
3. allocate out args(VIDDEC3_OutArgs*), but i did not allocate output buffer which seems unnecessary to me
4. call VIDDEC3_process(mCodec, mInBufs, mOutBufs, mInArgs, mOutArgs)
5. call VIDENC2_control(mCodec, XDM_GETSTATUS, (VIDENC2_DynamicParams *) mDynParams, (VIDENC2_Status *) mH264Status) mH264Status is allocated before.
6. call VIDDEC3_control(mCodec, XDM_GETBUFINFO, mDynParams, (VIDDEC3_Status*) mStatus)
but it does not work from the following logcat:
===================================================
11-02 13:18:46.284 4978 4988 D DecoderH264: [TI] (decoder_h264.cc, decodeInfo, 211)VIDDEC3_control - XDM_GETSTATUS err -1 maxNumDisplayBufs 0, outputWidth 0, outputHeight 0

11-02 13:18:46.284 4978 4988 D DecoderH264: [TI] (decoder_h264.cc, decodeInfo, 221)VIDDEC3_control - XDM_GETBUFINFO err 0 status minNumInBufs 1, minNumOutBufs 2, minInBufSize 2500000, minOutBufSize[0] 896, minOutBufSize[1] 896

11-02 13:18:46.284 4978 4988 D DecoderH264: [TI] (decoder_h264.cc, decodeInfo, 227)VIDDEC3_control - XDM_GETBUFINFO err 0 maxNumDisplayBufs 22, outputWidth 0, outputHeight 0
==================================================================
The maxNumDisplayBufs is not right for width/height 768x320, and outputWidth and outputHeight are not right also.
Did I set the wrong value to input/output or inArgs/outArgs, and how to set it.

thank you.

sorry, i set the wrong value toXDM_GETSTATUS for control. it's ok now.
but maxNumDisplayBufs is 22 for certain 264 stream, whose number is larger than the max reference frame count(16)

Hi Gao,
maxNumDisplayBufs depends on displaydelay also and not only num_ref_frames. In Decoder_Create(), application can set the displayDealy.
If it is set to IVIDDEC3_DISPLAY_DELAY_AUTO as done in viddec3test of omapdrmtest, decoder decides the display-delay.
Client applications can set displayDealay to IVIDDEC3_DISPLAY_DELAY_X (where X is 1 to 16).

If you look at viddec3test.c, it doesn't use maxNumDisplayBufs .
It calculates the display buffers as
decoder->num_outBuf = MIN(16, 32768 / ((width/16) * (height/16))) + 3;
This is based on the H264 spec ,higher the resolution lesser will be number of reference frames.

Ram

Thank you sam.
I have antother question. How to detect resolution change of stream.
I know there is a error number called IH264VDEC_ERR_PICSIZECHANGE, which is returned by codec when stream's resolution is changed.
Whether the following steps to play resolution changed media file are ok:
1. Call VIDDEC3_process, and until to detect the return value is IH264VDEC_ERR_PICSIZECHANGE
2. Set input buffer to EOS in order to drain out the output buffers
3. detect w/h from the new sps/pps, re-create engine and codec

Is that ok?

Hi Gao,
First three steps you mentioned here is for decode and playback till EOS.

I didn't understand your case. Is your application running out of buffers? After decode_create() and GetBUFINFO call, if application allocates the displaybuffers as suggested , there won't be issue with buffer drain.

Can you please give few details ?

Ram

Hi ram
Take decoding and playback till EOS as example.
When input buffer encounters EOS, Setting numBufs of XDM2_BufDesc to 0 and inputID of IVIDDEC3_InArgs NULL, then call XDM_FLUSH once and call VIDDEC3_process repeatedly to drain all the output buffers.

The question is I should find one free output buffer and call VIDDEC3_process each time, which is complex for application.
Whether calling VIDDEC3_process once then get all the output buffers once is OK? but it seems not work

Hi Ram,
I have another problem.

Application sometimes gets DCE_EIPC_CALL_FAIL error code from decoder, but it does not affect decoding procedure.
I can not figure out what's the meaming of that error code? How can i fix the error.

=============
libdce_linux.c:115: dce_buf_lock Error: ERROR: Failed eError == DCE_EOK error val -5MmRpc_use: Error: unable to declare buffer use
==============

Hi Gao,

You will observe this error 

dce_buf_lock Error: ERROR: Failed eError == DCE_EOK error val -5MmRpc_use: Error: unable to declare buffer use

when a buffer which is not released yet using dce_buf_unlock() and application is trying to submit the same buffer with dce_buf_lock() call.

Is it reproduced consistently for a specific stream at a specific frame or is it random?

Ram

It is not random and it's always occur at specific frame if format change happened in certain stream.

Hi Ram,
thank you for your patience, now my application is ok with 264 stream format.
But, i have another question with mpeg4 format. I want to parse the stream header to get the width and height.
Refering to appendix Dof MPEG4 decoder user guide, Parsing the header from mpeg4 stream seems not work well, whose procedure is the same as 264 stream.
calling VIDDEC3_process and return -1 error, and extendedError is XDM_UNSUPPORTEDPARAM. I cannot find the root cause.
The stream header containing VOS + VO + VOL +VOP is below,
11-13 21:09:04.698 17839 17847 D hexDump: 0000: 00, 00, 01, b0, f5, 00, 00, 01, b5, 09, 00, 00, 01, 00, 00, 00,
11-13 21:09:04.698 17839 17847 D hexDump: 0010: 01, 20, 00, 84, 5d, 4c, 28, a0, 21, e0, a3, 1f, 00, 00, 01, b6
Is the stream is right or not?

ok