Sven,
This is great, thanks again. Please excuse me for beginner questions.
I may have to bother you in the near future with more info :)
Thanks in advance
Gautam
On Tue, Feb 1, 2011 at 12:03 PM, Sven Alisch <sven...@gmx.de> wrote:
> Gautam,
>
>> my case I dont cut frames at all. So I assume that the calculation of
>> my pts and dts would be something like frameNR*40*90 like in your
>> case?
>
> For the dts you have got right. The pts you don't need to calculate because
> you get the pts as a present by avcodec_encode_video-function.
>
> regards,
> Sven
>
>> Thanks
>> Gautam
>>
>> On Tue, Feb 1, 2011 at 11:53 AM, Sven Alisch <sven...@gmx.de> wrote:
>>> Gautam,
>>>
>>>> What are your magic numbers in your math? 40*90 and 120*90?
>>>
>>> Sorry for the hard coded magic numbers. My code is quick and dirty. I have
>>> to do a finetuning now.
>>>
>>> 40*90 means 40 ms (because in germany the duration of a frame is 40 ms) and
>>> 90 because of the 90kHz by the standard for PTS-values.
>>>
>>>> Also where do you get decodeToFrame value?
>>>
>>> Oh this is my own variable. The background is following. My program should
>>> cut not only at keyframes. If I cut not at a keyframe, then I reencode my
>>> "open" GOP. So decodeToFrame tells me, how many frames to decode till the
>>> position where I have to reencode my stream.
>>>
>>> Example:
>>>
>>> My GOP structure
>>>
>>> IBPBPBPPP...
>>>
>>> Lets assume I want to cut my videofile at the 3'rd position. Now
>>> decodeToFrame is 3. But I have to decode the whole GOP including the first
>>> key frame. At the 3'rd frame I reencode and create a new coded shorter
>>> sequence. My english is bad, but did you understand?
>>>
>>> regards,
>>> Sven
>>>
>>>>
>>>>
>>>> On Tue, Feb 1, 2011 at 11:34 AM, Sven Alisch <sven...@gmx.de> wrote:
>>>>> Dear Gautam, dear Max,
>>>>>
>>>>> Thank you for your proposals. Now it works. The main problem (I think)
>>>>> depends on the avframe. This avframe was the direct output from the
>>>>> decoder. So this avframe contains many informations that disturbs the
>>>>> encoder. I show the solution (quick and dirty code! No memory cleanup and
>>>>> so on... ) at the end of my mail.
>>>>>
>>>>> @Max
>>>>>
>>>>> You've got right. It is better to comment the last one out.
>>>>>
>>>>> @Gautam
>>>>>
>>>>> Yes of course. No problem. Here is my code.
>>>>>
>>>>> if (frameFinished)
>>>>>
>>>>> // Here the decoder is finished and decode a frame
>>>>> from an existent h.264 stream
>>>>> {
>>>>> frameNr++;
>>>>>
>>>>> if (frameNr >= decodeToFrame)
>>>>> {
>>>>> AVCodecContext* c = t->streamContext->codec;
>>>>>
>>>>> AVFrame* newFrame = avcodec_alloc_frame();
>>>>> //
>>>>> Initialize a new frame
>>>>> int size = avpicture_get_size(c->pix_fmt, c->width,
>>>>> c->height);
>>>>> uint8_t* picture_buf = av_malloc(size);
>>>>> avpicture_fill((AVPicture *)newFrame, picture_buf,
>>>>> c->pix_fmt, c->width, c->height);
>>>>> av_picture_copy((AVPicture*)newFrame, (AVPicture*)avframe,
>>>>> c->pix_fmt, c->width, c->height); // Copy only the frame content
>>>>> without any other disturbing stuff
>>>>>
>>>>> newFrame->pts = (frameNr - decodeToFrame)*40*90;
>>>>> //
>>>>> Setting correct pts
>>>>>
>>>>> int out_size = avcodec_encode_video(c, video_outbuf,
>>>>> video_outbuf_size, newFrame);
>>>>> if (out_size > 0)
>>>>> {
>>>>> av_init_packet(&tmp_packet);
>>>>>
>>>>> if (c->coded_frame->pts != AV_NOPTS_VALUE)
>>>>> {
>>>>> tmp_packet.pts =
>>>>> av_rescale_q(c->coded_frame->pts,
>>>>>
>>>>> c->time_base,
>>>>>
>>>>> c->time_base) + 120*90;
>>>>> tmp_packet.dts = encodedFrames*40*90;
>>>>> }
>>>>> if(c->coded_frame->key_frame)
>>>>> tmp_packet.flags |= AV_PKT_FLAG_KEY;
>>>>> tmp_packet.stream_index= t->streamContext->index;
>>>>> tmp_packet.data= video_outbuf;
>>>>> tmp_packet.size= out_size;
>>>>> av_interleaved_write_frame(formatContext,
>>>>> &tmp_packet);
>>>>> encodedFrames++;
>>>>> }
>>>>> }
>>>>> }
>>>>>
>>>>> regards,
>>>>> Sven
>>>>>
>>>>> Am 01.02.2011 um 18:36 schrieb Gautam Muralidhar:
>>>>>
>>>>>> Sven,
>>>>>> I am seeing similar issues. How exactly are you writing your frames?
>>>>>> Do you think you can share your code inside the
>>>>>> if(outsize >0)
>>>>>> {
>>>>>>
>>>>>> }
>>>>>>
>>>>>> Thanks
>>>>>> Gautam
>>>>>> On Tue, Feb 1, 2011 at 6:15 AM, Max The Quantum <m.quan...@gmail.com>
>>>>>> wrote:
>>>>>>> I've tried your config, but uncommented all lines except
>>>>>>> //c->flags2|=CODEC_FLAG2_8X8DCT;
>>>>>>> //c->flags2^=CODEC_FLAG2_8X8DCT; // flags2=-dct8x8
>>>>>>> and commented out
>>>>>>> c->crf = 22;
>>>>>>>
>>>>>>> It seems that problem is caused by wrong value of c->keyint_min. What is
>>>>>>> default value for it?
>>>>>>> Try to set it manually to, say, 25 :)
>>>>>>>
>>>>>>> 2011/2/1 Sven Alisch <sven...@gmx.de>
>>>>>>>
>>>>>>>> Hello list,
>>>>>>>>
>>>>>>>> I want to (re-) encode some pictures I decoded with libav. The
>>>>>>>> following
>>>>>>>> code shows how I do that:
>>>>>>>>
>>>>>>>> First I decode an h.264 Stream and get pictures in an AVFrame
>>>>>>>> structure.
>>>>>>>> After doing this I want to encode them into an h.264 stream.
>>>>>>>> <snip>
>>>>>>>> bytesDecoded =
>>>>>>>> avcodec_decode_video2(m->videofile->VideoTrack->codec_context, avframe,
>>>>>>>> &frameFinished, &packet);
>>>>>>>>
>>>>>>>> if (frameFinished)
>>>>>>>> {
>>>>>>>> frameNr++;
>>>>>>>>
>>>>>>>> if (frameNr >= decodeToFrame)
>>>>>>>> {
>>>>>>>> AVCodecContext* c = t->streamContext->codec;
>>>>>>>> avframe->pts = (frameNr - decodeToFrame)*40*90;
>>>>>>>> int out_size = avcodec_encode_video(c, video_outbuf,
>>>>>>>> video_outbuf_size, avframe);
>>>>>>>> if (out_size > 0)
>>>>>>>> {
>>>>>>>> ...
>>>>>>>> }
>>>>>>>> <snap>
>>>>>>>>
>>>>>>>> My Encoding parameters for x264 are set in a function like this:
>>>>>>>>
>>>>>>>> bool h264_initEncoder(AVFormatContext* fc, tavtrack_t* track)
>>>>>>>> {
>>>>>>>> AVCodec* codec = NULL;
>>>>>>>> AVCodecContext* c = NULL;
>>>>>>>>
>>>>>>>> c = track->streamContext->codec;
>>>>>>>> c->profile = track->codec_context->profile; // original set
>>>>>>>> by
>>>>>>>> libavformat/libavcodec
>>>>>>>> c->level = track->codec_context->level; // original set
>>>>>>>> by
>>>>>>>> libavformat/libavcodec
>>>>>>>>
>>>>>>>> // Medium Profile
>>>>>>>> // libx264-medium.ffpreset preset
>>>>>>>> c->coder_type = FF_CODER_TYPE_AC; // coder = 1
>>>>>>>> c->flags |= CODEC_FLAG_LOOP_FILTER; // flags=+loop
>>>>>>>> c->me_cmp|= 1; //
>>>>>>>> cmp=+chroma, where CHROMA = 1
>>>>>>>> c->partitions |=
>>>>>>>> X264_PART_I8X8+X264_PART_I4X4+X264_PART_P8X8+X264_PART_B8X8;
>>>>>>>>
>>>>>>>> // partitions=+parti8x8+parti4x4+partp8x8+partb8x8
>>>>>>>> c->me_method=ME_HEX; // me_method=hex
>>>>>>>> c->me_subpel_quality = 7; // subq=7
>>>>>>>> c->me_range = 16; //
>>>>>>>> me_range=16
>>>>>>>> //c->gop_size = 250; // g=250
>>>>>>>> //c->keyint_min = 25; //
>>>>>>>> keyint_min=25
>>>>>>>> c->scenechange_threshold = 40; // sc_threshold=40
>>>>>>>> //c->i_quant_factor = 0.71; //
>>>>>>>> i_qfactor=0.71
>>>>>>>> //c->b_frame_strategy = 1; // b_strategy=1
>>>>>>>> c->qcompress = 0.6; //
>>>>>>>> qcomp=0.6
>>>>>>>> c->qmin = 10; //
>>>>>>>> qmin=10
>>>>>>>> c->qmax = 51; //
>>>>>>>> qmax=51
>>>>>>>> c->max_qdiff = 4; //
>>>>>>>> qdiff=4
>>>>>>>> c->max_b_frames = 3; // bf=3
>>>>>>>> c->refs = 3; //
>>>>>>>> refs=3
>>>>>>>> //c->directpred = 1; //
>>>>>>>> directpred=1
>>>>>>>> //c->trellis = 1;
>>>>>>>> //
>>>>>>>> trellis=1
>>>>>>>> c->flags2 |=
>>>>>>>> CODEC_FLAG2_BPYRAMID+CODEC_FLAG2_MIXED_REFS+CODEC_FLAG2_WPRED+CODEC_FLAG2_8X8DCT+CODEC_FLAG2_FASTPSKIP;
>>>>>>>>
>>>>>>>> // flags2=+bpyramid+mixed_refs+wpred+dct8x8+fastpskip
>>>>>>>> c->weighted_p_pred = 2; // wpredp=2
>>>>>>>>
>>>>>>>> // libx264-main.ffpreset preset
>>>>>>>> //c->flags2|=CODEC_FLAG2_8X8DCT;
>>>>>>>> //c->flags2^=CODEC_FLAG2_8X8DCT; //
>>>>>>>> flags2=-dct8x8
>>>>>>>> c->crf = 22;
>>>>>>>> codec = avcodec_find_encoder(c->codec_id);
>>>>>>>> if (!codec)
>>>>>>>> return false;
>>>>>>>>
>>>>>>>> if (avcodec_open(c, codec) < 0)
>>>>>>>> return false;
>>>>>>>>
>>>>>>>> return true;
>>>>>>>> }
>>>>>>>>
>>>>>>>> The Problem is, that the avcode_encode_video( ... ) works but no frame
>>>>>>>> will
>>>>>>>> be compressed. I get strange errors like this:
>>>>>>>>
>>>>>>>> [libx264 @ 0x101003600] specified frame type (5) at 0 is not compatible
>>>>>>>> with keyframe interval
>>>>>>>> [libx264 @ 0x101003600] specified frame type (5) at 1 is not compatible
>>>>>>>> with keyframe interval
>>>>>>>> [libx264 @ 0x101003600] specified frame type (3) at 2 is not compatible
>>>>>>>> with keyframe interval
>>>>>>>>
>>>>>>>> I get no frame. But why? Does anybody has an hint for me? Are my
>>>>>>>> parameters
>>>>>>>> wrong?
>>>>>>>>
>>>>>>>> regards,
>>>>>>>> Sven
>>>>>>>> _______________________________________________
>>>>>>>> libav-user mailing list
>>>>>>>> libav-user@mplayerhq.hu
>>>>>>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> libav-user mailing list
>>>>>>> libav-user@mplayerhq.hu
>>>>>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Gautam Muralidhar
>>>>>> Code Particle Inc.
>>>>>> (805)-501-0700
>>>>>> _______________________________________________
>>>>>> libav-user mailing list
>>>>>> libav-user@mplayerhq.hu
>>>>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>>>
>>>>> _______________________________________________
>>>>> libav-user mailing list
>>>>> libav-user@mplayerhq.hu
>>>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Gautam Muralidhar
>>>> Code Particle Inc.
>>>> (805)-501-0700
>>>> _______________________________________________
>>>> libav-user mailing list
>>>> libav-user@mplayerhq.hu
>>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>
>>> _______________________________________________
>>> libav-user mailing list
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>>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>>>
>>
>>
>>
>> --
>> Gautam Muralidhar
>> Code Particle Inc.
>> (805)-501-0700
>> _______________________________________________
>> libav-user mailing list
>> libav-user@mplayerhq.hu
>> https://lists.mplayerhq.hu/mailman/listinfo/libav-user
>
> _______________________________________________
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>
--
Gautam Muralidhar
Code Particle Inc.
(805)-501-0700
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