Recherche avancée

Sur d’autres sites (11254)

• Troll spirit

  15 juin 2013, par Mans — Law and liberty

  Last week’s announcements from the White House of steps being taken to begin fighting back against patent trolls, along with legislation passed in Vermont for the same purpose, are worthy of praise. Whether they prove effective or not, they are a sign of the problem finally having been recognised by the highest authorities. That said, only one aspect of the issue is addressed, that of non-practising entities or trolls. Little effort is being made to stymie troll-like behaviour from otherwise legitimate actors. While a stake is driven through the heart of the troll, its spirit remains free to roam the corporate world, and like a demon of darkness it possesses companies, compelling them to engage in the very practices we seek to eradicate.

  The demon

  The most damaging, when wielded by a troll, are those patents with vague or overly broad claims. These can easily be asserted against large numbers of alleged infringers, many of which likely choose to settle out of court rather than risk an expensive litigation process with uncertain outcome. Such negotiations are frequently subject to non-disclosure agreements prohibiting publication of details in any deals, or even the existence thereof. As a result, an accused has no way of assessing a fair price for a licence (assuming the patent is in fact valid), and the patent holder can thus extract from each would-be infringer precisely as much as they are willing or able to pay to avoid a lawsuit.

  At the root of this problem is the ease with which applications for the patents in question are granted. Given the volume of patent applications, it is hardly reasonable to demand a hugely more extensive examination process than currently takes place (although some improvements here are no doubt possible) ; after all, a speedy decision is in the best interest of all parties. The solution must evidently be found elsewhere.

  The exorcism

  An obvious cure to the problem is the abolishment of the patent system. As this is clearly not feasible today, more practical, albeit less effective, remedies must be sought. A few ideas follow.

  Make patent validity all or nothing

  Change the rules such that any claim being found invalid cancels the patent its entirety. With the full patent at stake in this manner, companies would be discouraged from gambling on frivolous claims and encouraged to conduct a more thorough background investigation before filing.

  Maintain a registry of licences

  Require that all patent licence agreements be filed in an open, easily searchable registry. This would hopefully increase fairness in licensing deals.

  Mandate reimbursement of licence fees for invalidated patents

  If a patent is challenged and found invalid, require that the owner reimburse any licence fees previously collected for the patent in question. Apart from being morally right, this could act as a deterrent to over-charging. The amount requested for a licence would likely be balanced against the risk of being made to pay it all back later, resulting in lower licence fees for low-confidence patents.

  These suggestions, alone or together, will not completely eradicate the problems of patent abuse. They are but small steps towards a more thorough overhaul of a system increasingly ill-suited to the nature and pace of modern technological development.

• Concatenating video files with ffmpeg, no sound in output file [on hold]

  1er septembre 2013, par Junaid

  I am concatenating different AVI video files. The input files has been specified in input.txt in the order required. First video file does not have sound track, but subsequent files have.

  After completion the resulting the operation, the output does not have audio !

  If I remove first video files from input then resulting video gets sound. So it means the output format follows the first item in input list. How can I solve this problem.

  Please suggest the options in ffmpeg ; not in any other tools like mencoder.

   ffmpeg -f concat -i inputs.txt -c copy test.avi
  
  ffmpeg version 1.1.git Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Jun 27 2013 09:22:45 with gcc 4.7 (Ubuntu/Linaro 4.7.3-1ubuntu1)
  
    configuration: --prefix=/home/junaid/ffmpeg_build --extra-cflags=-I/home/junaid/ffmpeg_build/include --extra-ldflags=-L/home/junaid/ffmpeg_build/lib --bindir=/home/junaid/bin --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab
  
    libavutil      52. 37.101 / 52. 37.101
  
    libavcodec     55. 17.100 / 55. 17.100
  
    libavformat    55.  9.100 / 55.  9.100
  
    libavdevice    55.  2.100 / 55.  2.100
  
    libavfilter     3. 77.101 /  3. 77.101
  
    libswscale      2.  3.100 /  2.  3.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  3.100 / 52.  3.100
  
  [concat @ 0x335a880] Invalid stream index 1
  
  [concat @ 0x335a880] max_analyze_duration 5000000 reached at 5000000 microseconds
  
  Input #0, concat, from 'inputs.txt':
  
    Duration: N/A, bitrate: N/A
  
      Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (xvid / 0x64697678), yuv420p, 720x480 [SAR 32:27 DAR 16:9], 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  Output #0, avi, to 'test.avi':
  
    Metadata:
  
      ISFT            : Lavf55.9.100
  
      Stream #0:0: Video: mpeg4 (xvid / 0x64697678), yuv420p, 720x480 [SAR 32:27 DAR 16:9], q=2-31, 25 fps, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
  Press [q] to stop, [?] for help
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 6368 times
  
  frame= 3793 fps=0.0 q=-1.0 size=   11108kB time=00:02:37.96 bitrate= 576.1kbits/Invalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 7173 times
  
  frame= 7921 fps=7801 q=-1.0 size=   22928kB time=00:05:30.16 bitrate= 568.9kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 6614 times
  
  frame=11729 fps=7688 q=-1.0 size=   27057kB time=00:08:08.96 bitrate= 453.3kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 6247 times
  
  frame=15324 fps=7565 q=-1.0 size=   44956kB time=00:10:38.92 bitrate= 576.4kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 6553 times
  
  frame=19096 fps=7516 q=-1.0 size=   64014kB time=00:13:16.24 bitrate= 658.6kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 6753 times
  
  frame=22983 fps=7558 q=-1.0 size=   79848kB time=00:15:58.36 bitrate= 682.5kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 7011 times
  
  frame=27019 fps=7610 q=-1.0 size=   94130kB time=00:18:46.68 bitrate= 684.4kbitsInvalid stream index 1
  
  [concat @ 0x335a880] Invalid stream index 1
  
      Last message repeated 1302 times
  
  frame=27772 fps=7658 q=-1.0 Lsize=   96618kB time=00:19:18.08 bitrate= 683.5kbits/s    
  
  video:95921kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.726908%

• Vulkan Validation Error from FFMPEG creating an image : VUID-VkImageCreateInfo-pNext-06811

  11 mars 2024, par cecil

  I have an AMD Radeon RX 7800 XT and am using the MESA video driver on Arch Linux.

  


  I've been struggling to work out the code to decode an H265 video with FFMPEG (using Vulkan Video) and get the decoded image into a texture I can render using Vulkan.

  


  At the point that I call avcodec_send_packet() the following debug information is output :

  


  [hevc @ 0x5190001a1380] Decoding VPS
[hevc @ 0x5190001a1380] Main profile bitstream
[hevc @ 0x5190001a1380] Decoding SPS
[hevc @ 0x5190001a1380] Main profile bitstream
[hevc @ 0x5190001a1380] Decoding VUI
[hevc @ 0x5190001a1380] Decoding PPS
[hevc @ 0x5190001a1380] Format vulkan chosen by get_format().
[hevc @ 0x5190001a1380] Format vulkan requires hwaccel initialisation.
[hevc @ 0x5190001a1380] Decoder capabilities for hevc profile "Main":
[hevc @ 0x5190001a1380]     Maximum level: 51 (stream 183)
[hevc @ 0x5190001a1380]     Width: from 16 to 8192
[hevc @ 0x5190001a1380]     Height: from 16 to 4352
[hevc @ 0x5190001a1380]     Width alignment: 16
[hevc @ 0x5190001a1380]     Height alignment: 16
[hevc @ 0x5190001a1380]     Bitstream offset alignment: 128
[hevc @ 0x5190001a1380]     Bitstream size alignment: 128
[hevc @ 0x5190001a1380]     Maximum references: 17
[hevc @ 0x5190001a1380]     Maximum active references: 8
[hevc @ 0x5190001a1380]     Codec header name: 'VK_STD_vulkan_video_codec_h265_decode' (driver), 'VK_STD_vulkan_video_codec_h265_decode' (compiled)
[hevc @ 0x5190001a1380]     Codec header version: 1.0.0 (driver), 1.0.0 (compiled)
[hevc @ 0x5190001a1380]     Decode modes: dedicated_dpb
[hevc @ 0x5190001a1380]     Capability flags: separate_references
[hevc @ 0x5190001a1380] Choosing best pixel format for decoding from 1:
[hevc @ 0x5190001a1380]     nv12* (Vulkan ID: 1000156003)
[hevc @ 0x5190001a1380] Chosen frame pixfmt: nv12 (Vulkan ID: 1000156003)
[ERROR] Validation Error: [ VUID-VkImageCreateInfo-pNext-06811 ] | MessageID = 0x30f4ac70 | vkCreateImage(): pCreateInfo specifies flags (VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT|VK_IMAGE_CREATE_EXTENDED_USAGE_BIT|VK_IMAGE_CREATE_ALIAS_BIT), format (VK_FORMAT_G8_B8R8_2PLANE_420_UNORM), imageType (VK_IMAGE_TYPE_2D), and tiling (VK_IMAGE_TILING_OPTIMAL) which are not supported by any of the supported video format properties for the video profiles specified in the VkVideoProfileListInfoKHR structure included in the pCreateInfo->pNext chain, as reported by vkGetPhysicalDeviceVideoFormatPropertiesKHR for the same video profiles and the image usage flags specified in pCreateInfo->usage (VK_IMAGE_USAGE_TRANSFER_SRC_BIT|VK_IMAGE_USAGE_SAMPLED_BIT|VK_IMAGE_USAGE_VIDEO_DECODE_DST_BIT_KHR). The Vulkan spec states: If the pNext chain includes a VkVideoProfileListInfoKHR structure with profileCount greater than 0, then supportedVideoFormat must be VK_TRUE (https://www.khronos.org/registry/vulkan/specs/1.3-extensions/html/vkspec.html#VUID-VkImageCreateInfo-pNext-06811)
[hevc @ 0x5190001a1380] Allocating 131072 bytes in bind index 0 for video session
[hevc @ 0x5190001a1380] Allocating 43614208 bytes in bind index 1 for video session
[hevc @ 0x5190001a1380] Vulkan decoder initialization sucessful


  


  I'm concerned about the validation error regarding an image creation. If I allow the program to continue decoding frames, this validation error appears a total of 6 times, but then stops as subsequent frames are decoded without any more validation errors.

  


  I'm unsure if this is a problem or not. FFMPEG reports "Vulkan decoder initialization sucessful" despite the validation error.

  


  I am unsure exactly what to do after calling avcodec_receive_frame() to get the decoded frame but did not want to try and proceed if there is a problem already with the images FFMPEG is creating.