FFMPEG Drawtext Time - ffmpeg

I'm trying to set when the drawtext of this FFmpeg command starts, I've tried with start_number but looks like it will not do the trick.
ffmpeg -i 1.mp4 -acodec aac -keyint_min 20 -r 20 -vcodec libx264 -crf 22 -b 1000k -bt 1000k -y -v 0 -bf 16 -threads 0 -vf drawtext="start_number=20:fontfile=/home/admin/script/impact.ttf:text='My Text':fontsize=15:fontcolor=white:x=w-30*t:y=10" output.mp4
I've tried different approaches, but nothing seems to work

start_number is a parameter for used for an input image sequence/pattern.
If you want to draw a text on a video starting from the 3rd second you could use:
ffmpeg -i 1.mp4 -vf drawtext="text='My Text':enable=gt(t\,3)" output.mp4
Please notice that encoding parameters were omitted and you should add them to meet your requirements.

Related

How to add a hard code of subs to this filter_complex

ffmpeg -ss 00:11:47.970 -t 3.090 -i "file.mkv" -ss 00:11:46.470 -t 1.500 -i "file" -ss 00:11:51.060 -t 0.960 -i "file.mkv" -an -c:v libvpx -crf 31 -b:v 10000k -y -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0][2:v:0][2:a:0]concat=n=3:v=1:a=1[outv][outa];[outv]scale='min(960,iw)':-1[outv];[outv]subtitles='file.srt'[outv]" -map [outv] file_out.webm -map [outa] file.mp3
I have a filter where take three different points in a file concat them together and scale them down this part works
Im looking to see how to add to the filter_complex a sub burn in step rendering the subs from the exact timings usings a file that I specify when I use the above code it doesn't work
The subtitles filter is receiving a concatenated stream. It does not contain the timestamps from the original segments. So the subtitles filter starts from the beginning. I'm assuming this is the problem when you said, "it doesn't work".
The simple method to solve this is to make temporary files then concatenate them.
Output segments
ffmpeg -ss 00:11:47.970 -t 3.090 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp1.webm
ffmpeg -ss 00:11:46.470 -t 1.500 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp2.webm
ffmpeg -ss 00:11:51.060 -t 0.960 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp3.webm
The timestamps are reset when fast seek is used (-ss before -i). -copytswill preserve the timestamps so the subtitles filter knows where to start the subtitles.
Make input.txt:
file 'temp1.webm'
file 'temp2.webm'
file 'temp3.webm'
Concatenate with the concat demuxer:
ffmpeg -f concat -i input.txt -c copy output.webm
-c copy enables stream copy mode so it avoids re-encoding to concatenate.

FFMPEG avoid_negative_ts makes video start not from keyframe

Let's say I want to cut part of the mp4 video and resize it from 1280x720 to 854x480.
My command looks like this:
ffmpeg -ss 45 -i source.mp4 -ss 10 -to 20 \
-acodec aac -ar 44100 -ac 2 -c:v libx264 \
-crf 26 -vf scale=854:480:force_original_aspect_ratio=decrease,pad=854:480:0:0,setsar=1/1,setdar=16/9 \
-video_track_timescale 29971 -pix_fmt yuv420p \
-map_metadata 0 -avoid_negative_ts 1 -y dest.mp4
The problem is, when I don't use option avoid_negative_ts, resulting video has some issues with time bases etc, therefore it cannot be later converted by other libs, for example Swift's AVFoundation.
But when I use this option - video does not start with keyframe.
By using ffprobe I see start_time=0.065997 or other times other than 0.
How can I use option avoid_negative_ts and have a video that starts with keyframe?

ffmpeg - Convert MP4 to WebM, poor results

I am trying to encode a video to webm for playing through a HTML5 video tag. I have these settings...
ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:a 128k -b:v 1M -c:a libopus output.webm
The results aren't great, video has lost lot's of it's sharpness. Looking at the original file I can see the bitrate is 1694kb/s.
Are there any settings I can add or change to improve the output? Would maybe a 2 pass encode improve things?
Try with
ffmpeg -i input.mp4 -c:v libvpx-vp9 -crf 30 -b:v 0 -b:a 128k -c:a libopus output.webm
Adjust the CRF value till the quality/size tradeoff is ok. Lower values produce bigger but better files.
Try to run two passes:
ffmpeg -i file.mp4 -b:v 0 -crf 30 -pass 1 -an -f webm -y /dev/null
ffmpeg -i file.mp4 -b:v 0 -crf 30 -pass 2 output.webm
From - https://trac.ffmpeg.org/wiki/Encode/VP9

Fade out in ffmpeg when creating a video from a still image is wonky?

I'm creating a video that:
uses a still image as a source
has a text overlay
fades in and out
has a silent stereo audio track.
So far, I have this, and it (almost) works correctly:
ffmpeg -f lavfi -i "aevalsrc=0|0" -loop 1 -i turtle-2.jpg -c:v libx264 -t 5 -r 30 -s 1920x1080 -aspect 16:9 -pix_fmt yuv420p -filter:v drawtext="fontsize=130:fontfile=comic.ttf:text='hello world':x=(w-text_w)*.25:y=(h-text_h)*.75",fade=in:0:60,fade=out:90:60 -acodec aac turtle11.mp4
The only problem is that the fade out doesn't seem to be going to black, even tho this is a 150 frame video and I believe I am following the ffmpeg documentation correctly.
The resulting video is here:
http://video.blivenyc.com/vid-from-image/turtle11.mp4
Any thoughts?
Well, I'm not sure why but this works, even tho it appears to be equivalent:
ffmpeg -f lavfi -i "aevalsrc=0|0" -loop 1 -i turtle-2.jpg -c:v libx264 -t 5 -r 30 -s 1920x1080 -aspect 16:9 -pix_fmt yuv420p -filter:v drawtext="fontsize=130:fontfile=comic.ttf:text='hello world':x=(w-text_w)*.25:y=(h-text_h)*.75",fade=t=in:st=0:d=1,fade=t=out:st=4:d=1 -acodec aac turtle12.mp4
Basically, frame-based syntax:
fade=in:0:60,fade=out:90:60
gets substitued with time-based:
fade=t=in:st=0:d=1,fade=t=out:st=4:d=1
And somehow it works. Not sure why this is.
The video stream on which the fade filter operates is not 150 frames long. Input and output framerates are different here. The use of -r to set output rate happens after all filtering is done. At that stage, ffmpeg will drop or duplicate frames to obtain the output rate.
The input rate for an image or image sequence is 25, unless expressly set otherwise. In your command, since there is no override, it's 25. So fade out of 60 frames starting at frame 90, will end at frame 125 (5 seconds x 25). ffmpeg will duplicate 5 frames of each input second to get it to 30.
To get the desired result, use
ffmpeg -f lavfi -i "aevalsrc=0|0" -loop 1 -framerate 30 -i turtle-2.jpg -c:v libx264 -t 5 -s 1920x1080 -aspect 16:9 -pix_fmt yuv420p -filter:v drawtext="fontsize=130:fontfile=comic.ttf:text='hello world':x=(w-text_w)*.25:y=(h-text_h)*.75",fade=in:0:60,fade=out:90:60 -acodec aac turtle11.mp4

how to set option of ffmpeg with libx264, I,P,B order?

I'm looking for a option of ffmpeg with libx264.
I want to operate it, like a hardware encoder with ordering of the fixed frame type.
IBBPBBPBBPBBPBB..IBBPBBPBBPBBP..IBBPBBP...
Please, give me a advice.
#!/bin/bash
INFILE=$1
IFILE=$1.ts
OPT_CRF="-g 120 -c:v libx264 -crf 18 -bf 2"
VAL_CBR="20000k"
OPT_COMMON="-c:v libx264 -b:v $VAL_CBR -minrate $VAL_CBR -maxrate $VAL_CBR -g 60"
ffmpeg -i $IFILE -vf crop=1920:1088:0:16 $OPT_COMMON -acodec copy ${INFILE}.1.ts
ffmpeg -i $IFILE -vf crop=1920:1088:1920:16 $OPT_COMMON -an ${INFILE}.2.ts
ffmpeg -i $IFILE -vf crop=1920:1088:0:1104 $OPT_COMMON -an ${INFILE}.3.ts
ffmpeg -i $IFILE -vf crop=1920:1088:1920:1104 $OPT_COMMON -an ${INFILE}.4.ts
If you want to force fixed P/B pattern than you should disable B-frames adaptive algorithm and specify max consecutive B-frames number by using old style global options, for example "-b_strategy 0 -bf 2" for PBBPBBPBBP... pattern. If you also want also fixed I-frames intervals than you need to disable scenecut detection algorithm also, for example "-sc_threshold 0 -g 50" for fixed 50 frames interval between I-frames. With new enough ffmpeg you can also use private libx264 options using -x264opts or -x264-params params.
So for fully fixed frame types pattern you may use any of below command lines (they should be equal):
ffmpeg -i $INFILE -c:v libx264 -b:v $BITRATE -sc_threshold 0 -g 50 -b_strategy 0 -bf 2 $OUTFILE
or
ffmpeg -i $INFILE -c:v libx264 -b:v $BITRATE -x264-params scenecut=0:keyint=50:b-adapt=0:bframes=2 $OUTFILE

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