Không thể cắt luồng video được truyền bằng FFmpeg

Cố gắng cắt một tệp video được lấy từ đầu vào tiêu chuẩn, nó chỉ hoạt động khi thời lượng bắt đầu lớn hơn 2.0 đối với một số video (không thành công đối với các video được quay từ điện thoại Android).

Khi ssđược đặt thành 2.0, nghĩa là ffmpeg -y -ss 00:00:02.0 -vcodec h264 -acodec aac -i pipe:0 -t 7 output_file.mp4, nó bị lỗi với đầu ra [mov,mp4,m4a,3gp,3g2,mj2 @ 0xecf920] stream 1, offset 0x65ea3: partial file pipe:0: Invalid data found when processing input.

Dưới đây là nhật ký đầy đủ:

$ cat camera_landscape.mp4 | ffmpeg -y -ss 00:00:02.0 -vcodec h264 -acodec aac -i pipe:0 -t 7 camera_landscape_test.mp4 
ffmpeg version 2.6.4 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.2 (Debian 4.9.2-10)
  configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector-strong -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libpulse --disable-mips32r2 --disable-mipsdspr1 --disable-mipsdspr2 --enable-libvidstab --enable-libzvbi --enable-avresample --disable-htmlpages --disable-podpages --enable-libutvideo --enable-libfdk-aac --enable-libx265 --enable-libiec61883 --enable-vaapi --enable-libdc1394 --disable-altivec --shlibdir=/usr/lib/x86_64-linux-gnu
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 11.102 /  5. 11.102
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'pipe:0':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2015-09-27 09:46:32
  Duration: 00:00:16.96, start: 0.000000, bitrate: N/A
    Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 640x480, 5744 kb/s, SAR 1:1 DAR 4:3, 28.68 fps, 28.67 tbr, 90k tbn, 180k tbc (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 95 kb/s (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : SoundHandle
[libx264 @ 0xee1000] using SAR=1/1
[libx264 @ 0xee1000] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0xee1000] profile High, level 3.0
[libx264 @ 0xee1000] 264 - core 146 - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 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=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'camera_landscape_test.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Lavf56.25.101
    Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 28.67 fps, 11008 tbn, 28.67 tbc (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : VideoHandle
      encoder         : Lavc56.26.100 libx264
    Stream #0:1(eng): Audio: aac (libfaac) ([64][0][0][0] / 0x0040), 48000 Hz, mono, s16, 128 kb/s (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : SoundHandle
      encoder         : Lavc56.26.100 libfaac
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfaac))
[mov,mp4,m4a,3gp,3g2,mj2 @ 0xecf920] stream 1, offset 0x65ea3: partial file
pipe:0: Invalid data found when processing input
frame=    0 fps=0.0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=N/A    
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

Bất cứ điều gì lớn hơn 2.0 đều thành công, như vậy:

$ cat camera_landscape.mp4 | ffmpeg -y -ss 00:00:02.1 -vcodec h264 -acodec aac -i pipe:0 -t 7 camera_landscape_test.mp4 
ffmpeg version 2.6.4 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.2 (Debian 4.9.2-10)
  configuration: --prefix=/usr --extra-cflags='-g -O2 -fstack-protector-strong -Wformat -Werror=format-security ' --extra-ldflags='-Wl,-z,relro' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-nonfree --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-libvpx --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-librtmp --enable-avfilter --enable-libfreetype --enable-libvo-aacenc --disable-decoder=amrnb --enable-libvo-amrwbenc --enable-libaacplus --libdir=/usr/lib/x86_64-linux-gnu --disable-vda --enable-libbluray --enable-libcdio --enable-gnutls --enable-frei0r --enable-openssl --enable-libass --enable-libopus --enable-fontconfig --enable-libpulse --disable-mips32r2 --disable-mipsdspr1 --disable-mipsdspr2 --enable-libvidstab --enable-libzvbi --enable-avresample --disable-htmlpages --disable-podpages --enable-libutvideo --enable-libfdk-aac --enable-libx265 --enable-libiec61883 --enable-vaapi --enable-libdc1394 --disable-altivec --shlibdir=/usr/lib/x86_64-linux-gnu
  libavutil      54. 20.100 / 54. 20.100
  libavcodec     56. 26.100 / 56. 26.100
  libavformat    56. 25.101 / 56. 25.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 11.102 /  5. 11.102
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'pipe:0':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    creation_time   : 2015-09-27 09:46:32
  Duration: 00:00:16.96, start: 0.000000, bitrate: N/A
    Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 640x480, 5744 kb/s, SAR 1:1 DAR 4:3, 28.68 fps, 28.67 tbr, 90k tbn, 180k tbc (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : VideoHandle
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 95 kb/s (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : SoundHandle
[libx264 @ 0xbe5000] using SAR=1/1
[libx264 @ 0xbe5000] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0xbe5000] profile High, level 3.0
[libx264 @ 0xbe5000] 264 - core 146 - H.264/MPEG-4 AVC codec - Copyleft 2003-2015 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 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=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'camera_landscape_test.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: isommp42
    encoder         : Lavf56.25.101
    Stream #0:0(eng): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 28.67 fps, 11008 tbn, 28.67 tbc (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : VideoHandle
      encoder         : Lavc56.26.100 libx264
    Stream #0:1(eng): Audio: aac (libfaac) ([64][0][0][0] / 0x0040), 48000 Hz, mono, s16, 128 kb/s (default)
    Metadata:
      creation_time   : 2015-09-27 09:46:32
      handler_name    : SoundHandle
      encoder         : Lavc56.26.100 libfaac
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfaac))
frame=  201 fps= 70 q=-1.0 Lsize=     543kB time=00:00:07.01 bitrate= 634.0kbits/s dup=1 drop=0    
video:465kB audio:71kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.238381%
[libx264 @ 0xbe5000] frame I:1     Avg QP:21.12  size:  5005
[libx264 @ 0xbe5000] frame P:200   Avg QP:22.80  size:  2354
[libx264 @ 0xbe5000] mb I  I16..4: 17.2% 82.0%  0.8%
[libx264 @ 0xbe5000] mb P  I16..4:  5.2%  9.7%  0.0%  P16..4: 53.7%  3.0%  3.4%  0.0%  0.0%    skip:25.0%
[libx264 @ 0xbe5000] 8x8 transform intra:65.7% inter:97.4%
[libx264 @ 0xbe5000] coded y,uvDC,uvAC intra: 27.7% 59.6% 0.0% inter: 20.1% 49.5% 0.0%
[libx264 @ 0xbe5000] i16 v,h,dc,p: 21% 31% 24% 24%
[libx264 @ 0xbe5000] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 12% 14% 58%  3%  3%  3%  3%  2%  2%
[libx264 @ 0xbe5000] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14%  6% 66%  4%  3%  3%  3%  1%  1%
[libx264 @ 0xbe5000] i8c dc,h,v,p: 62% 21% 16%  1%
[libx264 @ 0xbe5000] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0xbe5000] ref P L0: 38.2%  4.0% 33.1% 24.8%
[libx264 @ 0xbe5000] kb/s:542.91

Mọi thứ hoạt động tốt nếu đầu vào được tham chiếu dưới dạng tệp ( itrực tiếp), nhưng đường ống là bắt buộc. Khi thử nghiệm, một tệp Youtube cũng đã được thử nghiệm dẫn đến thành công. Câu hỏi ở đây là, tại sao thao tác này thất bại đối với video nhất định này và cách giải quyết nó.

Chỉnh sửa: Liên kết video tạm thời - http://tempsend.com/8F6F119BCA