[Libav-user] 回复： (no subject)

Wed Dec 21 19:22:03 EET 2016

I have tried your url, and it opens and plays correct in my software. I just updated to the 3.2.2 libs yesterday, I suggest you make sure you are working with the latest too. (I’m working in Windows, and pre-built libs can be dlowloaded from here: https://ffmpeg.zeranoe.com/builds/) Your URL plays fine, as it appears to be encoded as 15 fps; it issue I am trying to solve in my code right now is I can not get greater than 15 fps.

Anyway, to help you, here is my logic that opens IP cameras and live streams, up till the point where avcodec_open2() is called. I also fixed incorrect h264 decompressing yesterday, which this code includes. 

// setting up IP Camera options:
mp_opts = NULL;
av_dict_set( &mp_opts, "threads", "auto", 0 );	// if multi-threading is needed, do it, appears to be used
av_dict_set( &mp_opts, "max_delay", "1000000", 0 );	
av_dict_set( &mp_opts, "rtsp_transport", "tcp", 0 );
av_dict_set( &mp_opts, "framerate", "29.97", 0 );

if (avformat_open_input( &mp_format_context, camera_stream, NULL, &mp_opts ) !=0)
	return false; // failed to open stream

if (avformat_find_stream_info( mp_format_context, NULL ) < 0)
    return false; // Couldn't find stream information

m_video_stream = -1;
for (uint32 i = 0; i < (uint32)mp_format_context->nb_streams; i++)
{
    if (mp_format_context->streams[i]->codecpar->codec_type==AVMEDIA_TYPE_VIDEO) 
	{
      m_video_stream = i;
      break;
    }
}
if (m_video_stream == -1)
    return false;

AVCodecParameters* codecPars = mp_format_context->streams[m_video_stream]->codecpar;

 AVCodec* pCodec = avcodec_find_decoder( codecPars->codec_id );
 if (pCodec==NULL) 
    return false; // unsupported codec

mp_codec_context = avcodec_alloc_context3( pCodec );
if (avcodec_parameters_to_context( mp_codec_context, codecPars ) != 0)
    return false; // Failed to copy codec context

if (avcodec_open2( mp_codec_context, pCodec, &mp_opts ) < 0)
    return false; // failed to open codec

// and so on… I posted a few days ago the portion of my code that does the packet reading and display...

Sincerely,
-Blake Senftner

> On Dec 21, 2016, at 8:32 AM, sea <2509044372 at qq.com> wrote:
> 
> Thank you very much.  I download a   .mov file from http://www.hd-trailers.net/movie/rogue-one-a-star-wars-story/, but get the same result,  avcodec_open2 returns -1.
> 
> Function  av_dump_format gives .mov file information as :
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1.mov':
>   Metadata:
>     major_brand     : qt
>     minor_version   : 537199360
>     compatible_brands: qt
>     creation_time   : 2016-12-15 23:51:52
>     timecode        : 01:00:49:17
>   Duration: 00:00:43.00, start: 0.000000, bitrate: 1080 kb/s
>     Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 848x360, 997 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 48k tbc (default)
>     Metadata:
>       creation_time   : 2016-12-15 23:51:52
>       handler_name    : Apple Video Media Handler
>       encoder         : H.264
>     Stream #0:1(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
>     Metadata:
>       creation_time   : 2016-12-15 23:51:52
>       handler_name    : Time Code Media Handler
>       timecode        : 01:00:49:17
>     Stream #0:2(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 76 kb/s (default)
>     Metadata:
>       creation_time   : 2016-12-15 23:51:52
>       handler_name    : Apple Sound Media Handler
> 
> 
> I tried the stream address  rtmp://live.hkstv.hk.lxdns.com/live/hks,  the video stream has the type of h264.  avcodec_open2 returns -1.
> av_dump_format print as:
> Input #0, flv, from 'rtmp://live.hkstv.hk.lxdns.com/live/hks':
>   Metadata:
>     author          : PowerSmart
>     copyright       :
>     description     :
>     datarate        : 500
>     livetime        : 1470020146
>     timeshift       : 0
>   Duration: 01:00:00.00, start: 0.000000, bitrate: N/A
>     Stream #0:0: Video: h264 (Constrained Baseline), yuv420p, 640x480, 15.17 fps, 15 tbr, 1k tbn, 30 tbc
>     Stream #0:1: Audio: aac, 32000 Hz, stereo, fltp
> 
> 
> 
> 
> 
> 
> 
> ------------------ 原始邮件 ------------------
> 发件人: "Blake Senftner";<bsenftner at earthlink.net>;
> 发送时间: 2016年12月21日(星期三) 晚上11:46
> 收件人: "This list is about using libavcodec, libavformat, libavutil,libavdevice and libavfilter."<libav-user at ffmpeg.org>;
> 主题: Re: [Libav-user] (no subject)
> 
> Is the h264 file you are using available online to test against?
> 
> I have been using the h264 film trailers from here http://www.hd-trailers.net/movie/rogue-one-a-star-wars-story/
> 
> And they open and play without issue. Do you get the same issue with your software using one of these clips?
> 
> You may need to post your function that opens a stream up to the point where you call avcodec_open2()...
> 
> Sincerely,
> -Blake Senftner
> Computer Stuff
> 
>> On Dec 21, 2016, at 7:24 AM, sea <2509044372 at qq.com> wrote:
>> 
>> In transcoding project of LeiXiaoHua(demo of usage of filters), if I use media file with h264 video stream as input file, the function  avcodec_open2 will return -1.  Media file with video stream in other format, such as mpeg4, mjpeg return 0 (OK). Why ? Someone meets the same problem?
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