[FFmpeg-user] -movflags faststart revisited

Tue Feb 28 12:40:42 EET 2017

On Feb 27, 2017, at 6:55 PM, JD <jd1008 at gmail.com> wrote:

Well, could you at least provide the full args to ffplay, to play back an
incomplete transcode to mp4?

> On Mon, Feb 27, 2017 at 3:56 PM, PaulYurt <paulyurt at gmail.com> wrote:
> 
> JD, Can you substitute ffplay for ffmpeg in your tests? This way you can
> immediately see results.
> 
> Paul Yurt // Media Technologist // 310-439-8009
> 
> On Feb 25, 2017, at 10:28 PM, JD <jd1008 at gmail.com> wrote:
> 
> I retried to use this flag as it was indicated in a previous response by a
> user.
> Sorry that I was unable to continue on the original thread, because the
> gmail web
> interface deletes original message sent to this list by the OP, when the OP
> deletes the
> response from the list.
> 
> So, even though I corrected the usage of the flag, I am still unable to
> play the output
> file before ffmpeg finishes the transcoding :( :(
> 
> $ ~/bin/ffmpeg.d/ffmpeg -i video_Z11.mp4 -movflags faststart -vb 8000k -ab
> 384k -s 1920x1080 -y video_Z11-1920x1080.mp4
> ffmpeg version 3.2.4-static http://johnvansickle.com/ffmpeg/  Copyright
> (c)
> 2000-2017 the FFmpeg developers
> built with gcc 5.4.1 (Debian 5.4.1-5) 20170205
> configuration: --enable-gpl --enable-version3 --enable-static
> --disable-debug --disable-ffplay --disable-indev=sndio
> --disable-outdev=sndio --cc=gcc-5 --enable-fontconfig --enable-frei0r
> --enable-gnutls --enable-gray --enable-libass --enable-libfreetype
> --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb
> --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
> --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora
> --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis
> --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265
> --enable-libxvid --enable-libzimg
> libavutil      55. 34.101 / 55. 34.101
> libavcodec     57. 64.101 / 57. 64.101
> libavformat    57. 56.101 / 57. 56.101
> libavdevice    57.  1.100 / 57.  1.100
> libavfilter     6. 65.100 /  6. 65.100
> libswscale      4.  2.100 /  4.  2.100
> libswresample   2.  3.100 /  2.  3.100
> libpostproc    54.  1.100 / 54.  1.100
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'video_Z11.mp4':
> Metadata:
>   major_brand     : isom
>   minor_version   : 512
>   compatible_brands: isomiso2avc1mp41
>   creation_time   : 2016-11-29T13:42:34.000000Z
>   encoder         : Lavf56.1.0
> Duration: 02:22:55.48, start: 0.000000, bitrate: 379 kb/s
>   Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p,
> 480x360 [SAR 1:1 DAR 4:3], 246 kb/s, 29.95 fps, 29.97 tbr, 90k tbn, 59.91
> tbc (default)
>   Metadata:
>     creation_time   : 2016-11-29T13:42:34.000000Z
>     handler_name    : VideoHandler
>   Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
> stereo, fltp, 125 kb/s (default)
>   Metadata:
>     creation_time   : 2016-11-29T13:42:34.000000Z
>     handler_name    : SoundHandler
> [libx264 @ 0x5a3c240] using SAR=3/4
> [libx264 @ 0x5a3c240] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
> [libx264 @ 0x5a3c240] profile High, level 4.0
> [libx264 @ 0x5a3c240] 264 - core 148 r333 90a61ec - H.264/MPEG-4 AVC codec
> - Copyleft 2003-2017 - 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=3 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=abr mbtree=1 bitrate=8000 ratetol=1.0
> qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
> Output #0, mp4, to 'video_Z11-1920x1080.mp4':
> Metadata:
>   major_brand     : isom
>   minor_version   : 512
>   compatible_brands: isomiso2avc1mp41
>   encoder         : Lavf57.56.101
>   Stream #0:0(und): Video: h264 (libx264) ([33][0][0][0] / 0x0021),
> yuv420p, 1920x1080 [SAR 3:4 DAR 4:3], q=-1--1, 8000 kb/s, 29.97 fps, 30k
> tbn, 29.97 tbc (default)
>   Metadata:
>     creation_time   : 2016-11-29T13:42:34.000000Z
>     handler_name    : VideoHandler
>     encoder         : Lavc57.64.101 libx264
>   Side data:
>     cpb: bitrate max/min/avg: 0/0/8000000 buffer size: 0 vbv_delay: -1
>   Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz,
> stereo, fltp, 384 kb/s (default)
>   Metadata:
>     creation_time   : 2016-11-29T13:42:34.000000Z
>     handler_name    : SoundHandler
>     encoder         : Lavc57.64.101 aac
> Stream mapping:
> Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
> Stream #0:1 -> #0:1 (aac (native) -> aac (native))
> Press [q] to stop, [?] for help

You can pass the same encoding arguments to ffplay and observe the results on screen as quickly as the machine can generate output. 

It's one way I like to test my encoding parameters, assuming your machine is local. 

Paul Yurt // Media Technologist // 310-439-8009  