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• I have an application in flask where it streams a camera using ffmpeg, the problem is that I can not display the video from the camera using the GPU [closed]

  17 janvier, par Ruben

  I'll put you in context, I am using flask (python) to display a camera in the browser to stream it, for this I use the following Python code :

  


  command = [
     'ffmpeg',
     '-loglevel', 'warning',
     '-rtsp_transport', 'tcp',
     '-i', self.config['url'],
     '-map', '0:v:0', # fuerzo que solo procese el video
     '-vf', f'fps={self.config["fps"]},scale=640:360:force_original_aspect_ratio=decrease',
     '-c:v', 'h264_nvenc', # especificamos que queremos tirar de la gpu de nvidia
     '-preset', 'p7', # ajusta para la maxima calidad/velocidad (p1 mas rapida pero peor calidad - p7 más lento pero mejor calidad)
     '-qp', self.config['quality'], # control de calidad del codificador (0 [mejor calidad] - 51 [peor calidad])
     '-pix_fmt', 'yuv444p', # se mete explicitamente el formato de pixeles
     '-color_range', 'pc',
     '-an', # desactiva el audio
     '-f', 'image2pipe',
     'pipe:1'
] 

self.process = subprocess.Popen(
   command,
   stdout=subprocess.PIPE,
   stderr=subprocess.PIPE,
   bufsize=10**8
)


  


  The problem is that it does not display the video streaming, but it connects correctly to the camera.

  


  On the other hand, It show me the following warnings, which may have something to do with the display, it's probably the second warning that has to do with the pixel format :

  


  DEBUG :main:FFmpeg [camera1] : Guessed Channel Layout for Input Stream #0.1 : mono
DEBUG :main:FFmpeg [camera1] : [swscaler @ 0x560f70b78680] deprecated pixel format used, make sure you did set range correctly

  


  The server has different encodes installed :

  


  DEV.LS h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders : h264 h264_v4l2m2m h264_qsv h264_cuvid ) (encoders : libx264 libx264rgb h264_nvenc h264_omx h264_qsv h264_v4l2m2m h264_vaapi nvenc nvenc_h264 )

  


  Y uso el h264_nvenc, tambien el servidor tiene soporte de aceleración de hardware con :

  


  libavutil 56. 70.100 / 56. 70.100
libavcodec 58.134.100 / 58.134.100
libavformat 58. 76.100 / 58. 76.100
libavdevice 58. 13.100 / 58. 13.100
libavfilter 7.110.100 / 7.110.100
libswscale 5. 9.100 / 5. 9.100
libswresample 3. 9.100 / 3. 9.100
libpostproc 55. 9.100 / 55. 9.100
Hardware acceleration methods :
vdpau
cuda
vaapi
qsv
drm
opencl

  


  Between them h264_nvenc uses cuda

  


  I expand a little on the information it provides me when using h264_nvenc :

  


  Encoder h264_nvenc [NVIDIA NVENC H.264 encoder]:&#xA;    General capabilities: dr1 delay hardware&#xA;    Threading capabilities: none&#xA;    Supported hardware devices: cuda cuda&#xA;    Supported pixel formats: yuv420p nv12 p010le yuv444p p016le yuv444p16le bgr0 rgb0 cuda&#xA;h264_nvenc AVOptions:&#xA;  -preset            <int>        E..V....... Set the encoding preset (from 0 to 18) (default p4)&#xA;     default         0            E..V.......&#xA;     slow            1            E..V....... hq 2 passes&#xA;     medium          2            E..V....... hq 1 pass&#xA;     fast            3            E..V....... hp 1 pass&#xA;     hp              4            E..V.......&#xA;     hq              5            E..V.......&#xA;     bd              6            E..V.......&#xA;     ll              7            E..V....... low latency&#xA;     llhq            8            E..V....... low latency hq&#xA;     llhp            9            E..V....... low latency hp&#xA;     lossless        10           E..V.......&#xA;     losslesshp      11           E..V.......&#xA;     p1              12           E..V....... fastest (lowest quality)&#xA;     p2              13           E..V....... faster (lower quality)&#xA;     p3              14           E..V....... fast (low quality)&#xA;     p4              15           E..V....... medium (default)&#xA;     p5              16           E..V....... slow (good quality)&#xA;     p6              17           E..V....... slower (better quality)&#xA;     p7              18           E..V....... slowest (best quality)&#xA;  -tune              <int>        E..V....... Set the encoding tuning info (from 1 to 4) (default hq)&#xA;     hq              1            E..V....... High quality&#xA;     ll              2            E..V....... Low latency&#xA;     ull             3            E..V....... Ultra low latency&#xA;     lossless        4            E..V....... Lossless&#xA;  -profile           <int>        E..V....... Set the encoding profile (from 0 to 3) (default main)&#xA;     baseline        0            E..V.......&#xA;     main            1            E..V.......&#xA;     high            2            E..V.......&#xA;     high444p        3            E..V.......&#xA;  -level             <int>        E..V....... Set the encoding level restriction (from 0 to 62) (default auto)&#xA;     auto            0            E..V.......&#xA;     1               10           E..V.......&#xA;     1.0             10           E..V.......&#xA;     1b              9            E..V.......&#xA;     1.0b            9            E..V.......&#xA;     1.1             11           E..V.......&#xA;     1.2             12           E..V.......&#xA;     1.3             13           E..V.......&#xA;     2               20           E..V.......&#xA;     2.0             20           E..V.......&#xA;     2.1             21           E..V.......&#xA;     2.2             22           E..V.......&#xA;     3               30           E..V.......&#xA;     3.0             30           E..V.......&#xA;     3.1             31           E..V.......&#xA;     3.2             32           E..V.......&#xA;     4               40           E..V.......&#xA;     4.0             40           E..V.......&#xA;     4.1             41           E..V.......&#xA;     4.2             42           E..V.......&#xA;     5               50           E..V.......&#xA;     5.0             50           E..V.......&#xA;     5.1             51           E..V.......&#xA;     5.2             52           E..V.......&#xA;     6.0             60           E..V.......&#xA;     6.1             61           E..V.......&#xA;     6.2             62           E..V.......&#xA;  -rc                <int>        E..V....... Override the preset rate-control (from -1 to INT_MAX) (default -1)&#xA;     constqp         0            E..V....... Constant QP mode&#xA;     vbr             1            E..V....... Variable bitrate mode&#xA;     cbr             2            E..V....... Constant bitrate mode&#xA;     vbr_minqp       8388612      E..V....... Variable bitrate mode with MinQP (deprecated)&#xA;     ll_2pass_quality 8388616      E..V....... Multi-pass optimized for image quality (deprecated)&#xA;     ll_2pass_size   8388624      E..V....... Multi-pass optimized for constant frame size (deprecated)&#xA;     vbr_2pass       8388640      E..V....... Multi-pass variable bitrate mode (deprecated)&#xA;     cbr_ld_hq       8388616      E..V....... Constant bitrate low delay high quality mode&#xA;     cbr_hq          8388624      E..V....... Constant bitrate high quality mode&#xA;     vbr_hq          8388640      E..V....... Variable bitrate high quality mode&#xA;  -rc-lookahead      <int>        E..V....... Number of frames to look ahead for rate-control (from 0 to INT_MAX) (default 0)&#xA;  -surfaces          <int>        E..V....... Number of concurrent surfaces (from 0 to 64) (default 0)&#xA;  -cbr               <boolean>    E..V....... Use cbr encoding mode (default false)&#xA;  -2pass             <boolean>    E..V....... Use 2pass encoding mode (default auto)&#xA;  -gpu               <int>        E..V....... Selects which NVENC capable GPU to use. First GPU is 0, second is 1, and so on. (from -2 to INT_MAX) (default any)&#xA;     any             -1           E..V....... Pick the first device available&#xA;     list            -2           E..V....... List the available devices&#xA;  -delay             <int>        E..V....... Delay frame output by the given amount of frames (from 0 to INT_MAX) (default INT_MAX)&#xA;  -no-scenecut       <boolean>    E..V....... When lookahead is enabled, set this to 1 to disable adaptive I-frame insertion at scene cuts (default false)&#xA;  -forced-idr        <boolean>    E..V....... If forcing keyframes, force them as IDR frames. (default false)&#xA;  -b_adapt           <boolean>    E..V....... When lookahead is enabled, set this to 0 to disable adaptive B-frame decision (default true)&#xA;  -spatial-aq        <boolean>    E..V....... set to 1 to enable Spatial AQ (default false)&#xA;  -spatial_aq        <boolean>    E..V....... set to 1 to enable Spatial AQ (default false)&#xA;  -temporal-aq       <boolean>    E..V....... set to 1 to enable Temporal AQ (default false)&#xA;  -temporal_aq       <boolean>    E..V....... set to 1 to enable Temporal AQ (default false)&#xA;  -zerolatency       <boolean>    E..V....... Set 1 to indicate zero latency operation (no reordering delay) (default false)&#xA;  -nonref_p          <boolean>    E..V....... Set this to 1 to enable automatic insertion of non-reference P-frames (default false)&#xA;  -strict_gop        <boolean>    E..V....... Set 1 to minimize GOP-to-GOP rate fluctuations (default false)&#xA;  -aq-strength       <int>        E..V....... When Spatial AQ is enabled, this field is used to specify AQ strength. AQ strength scale is from 1 (low) - 15 (aggressive) (from 1 to 15) (default 8)&#xA;  -cq                <float>      E..V....... Set target quality level (0 to 51, 0 means automatic) for constant quality mode in VBR rate control (from 0 to 51) (default 0)&#xA;  -aud               <boolean>    E..V....... Use access unit delimiters (default false)&#xA;  -bluray-compat     <boolean>    E..V....... Bluray compatibility workarounds (default false)&#xA;  -init_qpP          <int>        E..V....... Initial QP value for P frame (from -1 to 51) (default -1)&#xA;  -init_qpB          <int>        E..V....... Initial QP value for B frame (from -1 to 51) (default -1)&#xA;  -init_qpI          <int>        E..V....... Initial QP value for I frame (from -1 to 51) (default -1)&#xA;  -qp                <int>        E..V....... Constant quantization parameter rate control method (from -1 to 51) (default -1)&#xA;  -weighted_pred     <int>        E..V....... Set 1 to enable weighted prediction (from 0 to 1) (default 0)&#xA;  -coder             <int>        E..V....... Coder type (from -1 to 2) (default default)&#xA;     default         -1           E..V.......&#xA;     auto            0            E..V.......&#xA;     cabac           1            E..V.......&#xA;     cavlc           2            E..V.......&#xA;     ac              1            E..V.......&#xA;     vlc             2            E..V.......&#xA;  -b_ref_mode        <int>        E..V....... Use B frames as references (from 0 to 2) (default disabled)&#xA;     disabled        0            E..V....... B frames will not be used for reference&#xA;     each            1            E..V....... Each B frame will be used for reference&#xA;     middle          2            E..V....... Only (number of B frames)/2 will be used for reference&#xA;  -a53cc             <boolean>    E..V....... Use A53 Closed Captions (if available) (default true)&#xA;  -dpb_size          <int>        E..V....... Specifies the DPB size used for encoding (0 means automatic) (from 0 to INT_MAX) (default 0)&#xA;  -multipass         <int>        E..V....... Set the multipass encoding (from 0 to 2) (default disabled)&#xA;     disabled        0            E..V....... Single Pass&#xA;     qres            1            E..V....... Two Pass encoding is enabled where first Pass is quarter resolution&#xA;     fullres         2            E..V....... Two Pass encoding is enabled where first Pass is full resolution&#xA;  -ldkfs             <int>        E..V....... Low delay key frame scale; Specifies the Scene Change frame size increase allowed in case of single frame VBV and CBR (from 0 to 255) (default 0)&#xA;</int></int></int></boolean></int></int></int></int></int></int></int></boolean></boolean></float></int></boolean></boolean></boolean></boolean></boolean></boolean></boolean></boolean></boolean></boolean></int></int></boolean></boolean></int></int></int></int></int></int></int>

  


  If anyone has some idea or needs more information to help me, I would appreciate it.

  


• Revision 33976 : bugs html

  27 décembre 2009, par cedric@… — Log

  bugs html

• Hacking the Popcorn Hour C-200

  3 mai 2010, par Mans — Hardware, MIPS

  Update : A new firmware version has been released since the publication of this article. I do not know if the procedure described below will work with the new version.

  The Popcorn Hour C-200 is a Linux-based media player with impressive specifications. At its heart is a Sigma Designs SMP8643 system on chip with a 667MHz MIPS 74Kf as main CPU, several co-processors, and 512MB of DRAM attached. Gigabit Ethernet, SATA, and USB provide connectivity with the world around it. With a modest $299 on the price tag, the temptation to repurpose the unit as a low-power server or cheap development board is hard to resist. This article shows how such a conversion can be achieved.
  

  Kernel

  The PCH runs a patched Linux 2.6.22.19 kernel. A source tarball is available from the manufacturer. This contains the sources with Sigma support patches, Con Kolivas’ patch set (scheduler tweaks), and assorted unrelated changes. Properly split patches are unfortunately not available. I have created a reduced patch against vanilla 2.6.22.19 with only Sigma-specific changes, available here.

  The installed kernel has a number of features disabled, notably PTY support and oprofile. We will use kexec to load a more friendly one.

  As might be expected, the PCH kernel does not have kexec support enabled. It does however, by virtue of using closed-source components, support module loading. This lets us turn kexec into a module and load it. A patch for this is available here. To build the module, apply the patch to the PCH sources and build using this configuration. This will produce two modules, kexec.ko and mips_kexec.ko. No other products of this build will be needed.

  The replacement kernel can be built from the PCH sources or, if one prefers, from vanilla 2.6.22.19 with the Sigma-only patch. For the latter case, this config provides a minimal starting point suitable for NFS-root.

  When configuring the kernel, make sure CONFIG_TANGOX_IGNORE_CMDLINE is enabled. Otherwise the command line will be overridden by a useless one stored in flash. A good command line can be set with CONFIG_CMDLINE (under “Kernel hacking” in menuconfig) or passed from kexec.

  Taking control

  In order to load our kexec module, we must first gain root privileges on the PCH, and here a few features of the system are working to our advantage :

  1. The PCH allows mounting any NFS export to access media files stored there.
  2. There is an HTTP server running. As root.
  3. This HTTP server can be readily instructed to fetch files from an NFS mount.
  4. Files with a name ending in .cgi are executed. As root.

  All we need do to profit from this is place the kexec modules, the kexec userspace tools, and a simple script on an NFS export. Once this is done, and the mount point configured on the PCH, a simple HTTP request will send the old kernel screaming to /dev/null, our shiny new kernel taking its place.

  The rootfs

  A kernel is mostly useless without a root filesystem containing tools and applications. A number of tools for cross-compiling a full system exist, each with its strengths and weaknesses. The only thing to look out for is the version of kernel headers used (usually a linux-headers package). As we will be running an old kernel, chances are the default version is too recent. Other than this, everything should be by the book.

  Assembling the parts

  Having gathered all the pieces, it is now time to assemble the hack. The following steps are suitable for an NFS-root system. Adaptation to a disk-based system is left as an exercise.

  1. Build a rootfs for MIPS 74Kf little endian. Make sure kernel headers used are no more recent than 2.6.22.x. Include a recent version of the kexec userspace tools.
  2. Fetch and unpack the PCH kernel sources.
  3. Apply the modular kexec patch.
  4. Using this config, build the modules and install them as usual to the rootfs. The version string must be 2.6.22.19-19-4.
  5. From either the same kernel sources or plain 2.6.22.19 with Sigma patches, build a vmlinux and (optionally) modules using this config. Modify the compiled-in command line to point to the correct rootfs. Set the version string to something other than in the previous step.
  6. Copy vmlinux to any directory in the rootfs.
  7. Copy kexec.sh and kexec.cgi to the same directory as vmlinux.
  8. Export the rootfs over NFS with full read/write permissions for the PCH.
  9. Power on the PCH, and update to latest firmware.
  10. Configure an NFS mount of the rootfs.
  11. Navigate to the rootfs in the PCH UI. A directory listing of bin, dev, etc. should be displayed.
  12. On the host system, run the kexec.sh script with the target hostname or IP address as argument.
  13. If all goes well, the new kernel will boot and mount the rootfs.

  Serial console

  A serial console is indispensable for solving boot problems. The PCH board has two UART connectors. We will use the one labeled UART0. The pinout is as follows (not standard PC pinout).

          +-----------+
         2| * * * * * |10
         1| * * * * * |9
          -----------+
            J7 UART0
      /---------------------/ board edge
  

  Pin	Function
  1	+5V
  5	Rx
  6	Tx
  10	GND

  The signals are 3.3V so a converter, e.g. MAX202, is required for connecting this to a PC serial port. The default port settings are 115200 bps 8n1.