[Libav-user] Decoding single NALUs from x264 programmatically (no luck even with parser), works fine with concatenated NALUs

[Sergey Fedorov]

You should split the stream to NAL units anyway before passing to decoder.
That's what I know about it )


2013/7/8 Faraz Khan <faraz at screenhero.com>

> Sergey,
> Just tried  - setting decoderContext->flags2 to CODEC_FLAG2_CHUNKS also
> doesnt work (with or without parser!) Is there something special that needs
> to be done?
>
> Decoder keeps saying:
>
> *Screenhero[45392:13803] Current profile doesn't provide more RBSP data
> in PPS, skipping*
>
> *2013-07-07 13:47:38.105 Screenhero[45392:13803] Frame size received is
> 8476*
>
> *2013-07-07 13:47:38.107 Screenhero[45392:13803] out of range intra
> chroma pred mode at 67358720 -1583242847*
>
> *2013-07-07 13:47:38.107 Screenhero[45392:13803] error while decoding MB
> 67358720 -1583242847*
>
> *2013-07-07 13:47:38.108 Screenhero[45392:13803] out of range intra
> chroma pred mode at 67358720 -1583242847*
>
> *2013-07-07 13:47:38.108 Screenhero[45392:13803] error while decoding MB
> 67358720 -1583242847*
>
> *2013-07-07 13:47:38.119 Screenhero[45392:13803] Frame size received is
> 6464*
>
> *2013-07-07 13:47:38.120 Screenhero[45392:13803] Frame size received is
> 1287*
>
> *2013-07-07 13:47:38.126 Screenhero[45392:13803] Frame size received is
> 9938*
>
> *2013-07-07 13:47:38.127 Screenhero[45392:13803] cbp too large (67358720)
> at -1583242847 67358792*
>
> *2013-07-07 13:47:38.127 Screenhero[45392:13803] error while decoding MB
> 67358720 -1583242847*
>
> *2013-07-07 13:47:38.127 Screenhero[45392:13803] negative number of zero
> coeffs at 67358720 -1583242847*
>
> *2013-07-07 13:47:38.128 Screenhero[45392:13803] error while decoding MB
> 67358720 -1583242847*
>
> *2013-07-07 13:47:38.134 Screenhero[45392:13803] Frame size received is
> 2574*
>
> *
> *
>
> *Thanks!*
>
> *
> *
>
>
> On Sun, Jul 7, 2013 at 1:15 PM, Faraz Khan <faraz at screenhero.com> wrote:
>
>> Sergey,
>> I did not - is that supposed to do the trick? Would we need a parser in
>> that scenario?
>>
>>
>>
>> On Sun, Jul 7, 2013 at 12:13 AM, Sergey Fedorov <
>> night.rain.whisper at gmail.com> wrote:
>>
>>> Did you try using CODEC_FLAG2_CHUNKS?
>>>
>>>
>>> 2013/7/6 Attila Sukosd <attila.sukosd at gmail.com>
>>>
>>>> Hi guys,
>>>>
>>>> There was this thread about decoding NALUs one-by-one with
>>>> parser2/decode2 and I'm having exactly the same issue.
>>>>
>>>> I have x264 creating a bunch of NALUs, in annex_b and repeate_headers,
>>>> and trying to decode them one by one on the client side. When I concatenate
>>>> all the NALUs per frame into one large packet, and feed that directly into
>>>> avcodec_decode_video2, everything is fine, the decode is successful.
>>>> However, when I try to feed single NALs directly to
>>>> avcodec_decode_video2, it spits out a bunch of errors. After searching for
>>>> a while on the net, I read some place that certain types of NALs affect the
>>>> rest of the data stream, and they need to be group together.
>>>> I've tried to run the NALs through av_parser_parse2 and tried to decode
>>>> the output buffer when the output size was larger than zero, however, after
>>>> looking at the output buffer contents, it seems like while the output size
>>>> seems reasonable (around the size of the NALs or a combination of a number
>>>> of previous NALs), the output buffer content contains 3-4 bytes, and the
>>>> rest is zero.
>>>>
>>>> The decoding looks like this:
>>>>
>>>>  ret = av_parser_parse2(decoder->pParserCtx, decoder->pCodecCtx,
>>>> decoder->tmp_data, &outsize, buff, size, 0, 0, AV_NOPTS_VALUE);
>>>>  printf("%p buff, %p outdata, consumed %d, %d bufsize, %d outsize\n",
>>>> buff, decoder->tmp_data,ret, size, outsize);
>>>>  disp_buff(decoder->tmp_data, 50);
>>>>
>>>>  if (outsize <= 0) return 0;
>>>>
>>>>  decoder->avpkt.flags = AV_PKT_FLAG_KEY;
>>>>  decoder->avpkt.data = decoder->tmp_data;
>>>>  decoder->avpkt.size = outsize;
>>>>
>>>>   got_picture = 0;
>>>>   if ((ret = avcodec_decode_video2(decoder->pCodecCtx, decoder->pFrame,
>>>> &got_picture, &decoder->avpkt)) < 0) {
>>>>                 LOGE(__FUNCTION__, "H264 decoding failed!\n");
>>>>                 return -1;
>>>>   }
>>>>
>>>>
>>>> Could someone shed some light on if I'm really off the right track? or
>>>> am I just missing something very trivial?
>>>>
>>>>
>>>> Best Regards,
>>>>
>>>> Attila
>>>>
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>>>>
>>>>
>>>
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>>
>>
>> --
>>
>> --
>> Faraz Khan
>> Simple Collaboration Screensharing
>> www.screenhero.com
>>
>
>
>
> --
>
> --
> Faraz Khan
> Simple Collaboration Screensharing
> www.screenhero.com
>
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