Recherche avancée

Sur d’autres sites (8563)

• ffmpeg - HLS stream audio error between segmets

  2 février 2019, par Carl

  I have a huge amount of mp4 files to create HLS segments from, more than 200 hours worth of files. I don’t see the point of re-encoding these videos because they are already in mp4 format. I’m using the following command which copies the video into segments instead of encoding it again.

  ffmpeg -i filename.mp4 -codec: copy -start_number 0 -hls_time 4 -hls_list_size 0 -f hls filename.m3u8

  The problem is when it comes to stitching these segments, I’m getting micro audio errors between segments. It’s hard to explain but imagine somebody turning audio off for 0.1 seconds. I doesn’t happen in all of the segments but in 20%-30% of them. Is there anything I can do stop these errors from popping up apart from reencoding all the videos. There are no problems with video btw.

  Here’s media info from one of the files :

  General
  Complete name : C :\video_test\video_file.mp4
  Format : MPEG-4
  Format profile : Base Media / Version 2
  Codec ID : mp42 (isom/iso2/avc1/mp41/mp42)
  File size : 45.7 MiB
  Duration : 7 min 34 s
  Overall bit rate mode : Variable
  Overall bit rate : 844 kb/s
  Writing application : Lavf53.32.100
  

  Video
  ID : 1
  Format : AVC
  Format/Info : Advanced Video Codec
  Format profile : High@L4
  Format settings, CABAC : Yes
  Format settings, RefFrames : 8 frames
  Codec ID : avc1
  Codec ID/Info : Advanced Video Coding
  Duration : 7 min 34 s
  Bit rate : 767 kb/s
  Width : 1 280 pixels
  Height : 720 pixels
  Display aspect ratio : 16:9
  Frame rate mode : Constant
  Frame rate : 30.000 FPS
  Color space : YUV
  Chroma subsampling : 4:2:0
  Bit depth : 8 bits
  Scan type : Progressive
  Bits/(Pixel*Frame) : 0.028
  Stream size : 41.5 MiB (91%)
  Writing library : x264 core 136
  Encoding settings : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x113 / me=umh / subme=6 / psy=0 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=48 / lookahead_threads=5 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=0 / keyint=60 / keyint_min=30 / scenecut=0 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

  Audio
  ID : 2
  Format : AAC
  Format/Info : Advanced Audio Codec
  Format profile : LC
  Codec ID : 40
  Duration : 7 min 34 s
  Bit rate mode : Variable
  Bit rate : 72.0 kb/s
  Maximum bit rate : 96.0 kb/s
  Channel(s) : 2 channels
  Channel positions : Front : L R
  Sampling rate : 44.1 kHz
  Frame rate : 43.066 FPS (1024 SPF)
  Compression mode : Lossy
  Stream size : 3.92 MiB (9%)
  Language : English
  Default : Yes
  Alternate group : 1
  

  Edit : I just tried copying video and reencoding the audio with the following command but problem still persists.

  ffmpeg -i filename.mp4 -vcodec copy -c:a aac -ar 48000 -b:a 128k -start_number 0 -hls_time 4 -hls_list_size 0  -f hls filename.m3u8

• How to force specific AVInputFormat in code (FFMPEG) ?

  18 février 2020, par kugipark

  ++Plaease understand that maybe some words or sentences could not be correct English.++

  I’m novice programmer and developing a video player app for Android which can play 5ch .avi video from http. It based on ffplay.c in FFMPEG libarary.

  Currently I have 2 problems for this below. It has occured only in android devices.

  ---

  1) Too much time taken for detecting format.

  • opening and finding stream info takes more than a minute when I trying to open 5ch video source whereas normal .mp4 (h264) source open almost immediately.

  2) Demuxing is too slow when it comes to large size video.

  • If the resolution of video getting larger, then displaying frame rate getting slower even though there are enough memory, network and CPU resources physically.

  To resolve my problem, I tried to force the format and decoders but I couldn’t found some information for specifying the input source in code level.
  The official doc site only refers to a sentence about those parameters like "If non-NULL, this parameter forces a specific input format. Otherwise the format is autodetected.". So I don’t have any clues how to set the number of streams, decoders, decoders’ private options, and etc. (And also which parameters should I manage.) If someone knows how to set the options(like AVDictionary), and pass to the av functions, please let me know an exmple. The source contains 2 video streams, 1 audio stream, and 2 more extra streams (for custom data like gps). The stream information of video is below. I printed it manually, and these are auto-detected information.

      ---------- File format information ----------
  
  flags=2097152
  
  video_codec_id=0 (NONE)
  
  audio_codec_id=0 (NONE)
  
  ctx_flags=0
  
  data_codec_id=0 (NONE)
  
  format_whitelist=(null)
  
  iformat=0xa19d0d2c
  
  ---------- Stream information ----------
  
  stream 1 of 5:
  
  ----- common ----------
  
  bit_rate: 11383235
  
  bits_per_coded_sample: 24
  
  bits_per_raw_sample: 0
  
  codec_id: 0x1C (H264)
  
  codec_tag: 875967048
  
  extradata_size: 0
  
  level: -99
  
  profile: -99
  
  sample_rate: 0
  
  ----- Video Stream ----------
  
  chroma_location: 0
  
  color_primaries: 2
  
  color_space: 2
  
  color_trc: 2
  
  field_order: 0
  
  format: -1 (NONE)
  
  height: 1080
  
  width: 1920
  
  sample_aspect_ratio.den: 1
  
  sample_aspect_ratio.num: 0
  
  video_delay: 0
  
  ----------------------------------------
  
  stream 2 of 5:
  
  ----- common ----------
  
  bit_rate: 6185438
  
  bits_per_coded_sample: 24
  
  bits_per_raw_sample: 0
  
  codec_id: 0x1C (H264)
  
  codec_tag: 875967048
  
  extradata_size: 0
  
  level: -99
  
  profile: -99
  
  sample_rate: 0
  
  ----- Video Stream ----------
  
  chroma_location: 0
  
  color_primaries: 2
  
  color_space: 2
  
  color_trc: 2
  
  field_order: 0
  
  format: -1 (NONE)
  
  height: 720
  
  width: 1280
  
  sample_aspect_ratio.den: 1
  
  sample_aspect_ratio.num: 0
  
  video_delay: 0
  
  ----------------------------------------
  
  stream 3 of 5:
  
  ----- common ----------
  
  bit_rate: 352800
  
  bits_per_coded_sample: 16
  
  bits_per_raw_sample: 0
  
  codec_id: 0x10000 (PCM_S16LE)
  
  codec_tag: 1
  
  extradata_size: 0
  
  level: -99
  
  profile: -99
  
  sample_rate: 22050
  
  ----- Audio Stream ----------
  
  block_align: 2
  
  channels: 1
  
  channel_layout: 0
  
  color_range: 0
  
  frame_size: 0
  
  initial_padding: 0
  
  seek_preroll: 0
  
  trailing_padding: 0
  
  ----------------------------------------
  
  stream 4 of 5:
  
  ----- common ----------
  
  bit_rate: 15625
  
  bits_per_coded_sample: 0
  
  bits_per_raw_sample: 0
  
  codec_id: 0x0 (NONE)
  
  codec_tag: 0
  
  extradata_size: 0
  
  level: -99
  
  profile: -99
  
  sample_rate: 0
  
  ----- Subtitle Stream ----------
  
  ----------------------------------------
  
  stream 5 of 5:
  
  ----- common ----------
  
  bit_rate: 33862
  
  bits_per_coded_sample: 0
  
  bits_per_raw_sample: 0
  
  codec_id: 0x0 (NONE)
  
  codec_tag: 0
  
  extradata_size: 0
  
  level: -99
  
  profile: -99
  
  sample_rate: 0
  
  ----- Subtitle Stream ----------

• FFmpeg conversion to Photo-JPEG is blocky [duplicate]

  26 mai 2017, par Richard210363

  This question already has an answer here :

  • ffmpeg generate higher quality images for MJPEG encoding
    
    1 answer
    

  I am converting .mp4 files to .mov with the Photo-JPEG codec to use in After Effects to reduce render times.

  I have looked up the FFmpeg commands to do this and come up with :

  ffmpeg -i tower-bridge.mp4 -an -pix_fmt yuvj420p -vcodec mjpeg -f mov -y tower-bridge.mov 

  This works but when I look at the output video it is quite blocky ; like a mosaic.

  During the conversion I get this message :

  [swscaler @ 0000000008c97fe0] deprecated pixel format used, make sure you did set range correctly

  Research on-line suggests I can ignore this message.

  What can I do to improve the output quality ?

  MediaInfo report on Input file :

  Complete name : F :\london-tower-bridge.mp4
  Format : MPEG-4
  Format profile : Base Media
  Codec ID : isom (isom/avc1/mp42)
  File size : 18.7 MiB
  Duration : 13 s 625 ms
  Overall bit rate : 11.5 Mb/s
  

  ID : 1
  Format : AVC
  Format/Info : Advanced Video Codec
  Format profile : Baseline@L4
  Format settings, CABAC : No
  Format settings, ReFrames : 3 frames
  Codec ID : avc1
  Codec ID/Info : Advanced Video Coding
  Duration : 13 s 625 ms
  Bit rate : 11.5 Mb/s
  Maximum bit rate : 26.8 Mb/s
  Width : 1 920 pixels
  Height : 1 080 pixels
  Display aspect ratio : 16:9
  Frame rate mode : Constant
  Frame rate : 24.000 FPS
  Color space : YUV
  Chroma subsampling : 4:2:0
  Bit depth : 8 bits
  Scan type : Progressive
  Bits/(Pixel*Frame) : 0.231
  Stream size : 18.7 MiB (100%)
  Writing library : Zencoder Video Encoding System
  

  MediaInfo report on Output file :

  Complete name : F :\london-tower-bridge.mov
  Format : MPEG-4
  Format profile : QuickTime
  Codec ID : qt 0000.02 (qt )
  File size : 16.1 MiB
  Duration : 13 s 625 ms
  Overall bit rate mode : Variable
  Overall bit rate : 9 912 kb/s
  Writing application : Lavf57.72.101
  

  ID : 1
  Format : JPEG
  Codec ID : jpeg
  Duration : 13 s 625 ms
  Bit rate mode : Variable
  Bit rate : 9 910 kb/s
  Width : 1 920 pixels
  Height : 1 080 pixels
  Display aspect ratio : 16:9
  Frame rate mode : Constant
  Frame rate : 24.000 FPS
  Color space : YUV
  Chroma subsampling : 4:2:0
  Bit depth : 8 bits
  Scan type : Progressive
  Compression mode : Lossy
  Bits/(Pixel*Frame) : 0.199
  Stream size : 16.1 MiB (100%)
  Language : English