How to downscale video without loosing quality?

[dc7800]

i have several videos of resolution 1920 x 1088.
My Sony HD LED TV can only play videos of maximum resolution 1920 x 1080.

so, i want to downscale them to 1920 x 1080.
Without loosing video quality.

Can expert help me for this in FFmpeg or in other tools?

[Bridgy]

How come your files are 1920 x 1088, that seems rather strange ?

I am sure that one of the experts in here can help better than i can.

[Sharc]

1088 is the internal mod16 padded size, used by the encoder. Usually it is cropped to 1080. If it is really 1088 and the player refuses to play it one can just crop it to 1080.

In ffmpeg you can try something like

ffmpeg -i "your_source" -c:a copy -c:v libx264 -preset slow -crf 20 -pix_fmt yuv420p -vf "crop=1920:1080:0:0" "cropped.mp4"

[videoAI]

@dc7800
you mentioned "several videos" ..

try:
Best Video Converter
it is a bit outdated but it uses FFmpeg (hint: update FFmpeg binaries, if needed), and allows for batch conversion and supports multiple CPU cores, MMX / SSE instructions and GPU acceleration.

Tip: drop [aria2c.exe] in the folder .. for speed.

Another method will be to try lossless crop using Clever FFmpeg assuming your Sony TV supports it.
@ProWo

It is not in fact necessary to re-encode, if the player you use supports crop parameter in the video bitstream (x264, hevc).

Code:
ffmpeg -i "input.mp4" -codec copy -bsf:v h264_metadata=crop_top=128 "output_cropped.mp4"
this will crop 128 pixels from the top of a mp4/x264 video, if the player supports the video bitstream tag.

(for x265: hevc_metadata=crop_top=128)

[dc7800]

thanks to all for help

[jagabo]

If it's h.264 or h.265 video it's possible to set the codec's internal cropping values without re-encoding (codecs often work in mod 16 frame sizes internally, then crop to the desired frame size for output). Since there's no re-encoding it's very fast and there is no quality loss (aside from the pixels that are cropped away).

See: https://www.videohelp.com/software/H264info

[Santiago]

Shutter Encoder and HandBrake are free programs. There is no noticeable difference in video quality.

[jagabo]

ffmpeg can modify the h.264 flags too. See the bitream filter's h.264 and h.265 metadata's crop_arguments:

https://ffmpeg.org/ffmpeg-bitstream-filters.html#h264_005fmetadata
https://ffmpeg.org/ffmpeg-bitstream-filters.html#hevc_005fmetadata

Something like:

ffmpeg -i 1088.mov -c copy -bsf:v h264_metadata=crop_bottom=8 1080.mov

You might also need to specify the aspect ratio and the frame sized flagged at the container level. Like with h264info, this method is lossless.

[Cornucopia]

Those are good answers.
To address the side issue of "WILL DOWNSCALING VIDEO LOSE QUALITY?", the answer is YES, it always loses quality. How much & how noticeable vary, depending on size ratios, settings, resulting codec, settings & bitrate, scaling algorithm, your sensitivity, etc.


Scott

[dc7800]

ffmpeg can modify the h.264 flags too. See the bitream filter's h.264 and h.265 metadata's crop_arguments:

https://ffmpeg.org/ffmpeg-bitstream-filters.html#h264_005fmetadata
https://ffmpeg.org/ffmpeg-bitstream-filters.html#hevc_005fmetadata

Something like:

ffmpeg -i 1088.mov -c copy -bsf:v h264_metadata=crop_bottom=8 1080.mov

You might also need to specify the aspect ratio and the frame sized flagged at the container level. Like with h264info, this method is lossless.

Please check

General
Complete name : 2.mp4
Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 1.96 GiB
Duration : 23 min 1 s
Overall bit rate mode : Variable
Overall bit rate : 12.2 Mb/s
Writing application : Lavf57.83.100

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 23 min 1 s
Bit rate : 12.0 Mb/s
Width : 1 920 pixels
Height : 1 088 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) : 0.239
Stream size : 1.93 GiB (98%)
Writing library : x264 core 138
Encoding settings : cabac=1 / ref=4 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 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=0 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=48 / keyint_min=4 / scenecut=0 / intra_refresh=0 / rc_lookahead=48 / rc=abr / mbtree=1 / bitrate=12000 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=16800 / vbv_bufsize=24000 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Codec configuration box : avcC

Audio
ID : 2
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 23 min 1 s
Bit rate mode : Variable
Bit rate : 192 kb/s
Maximum bit rate : 195 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 31.6 MiB (2%)
Default : Yes
Alternate group : 1

[salini]

If you're looking for a simple way to downscale videos without quality loss, FFmpeg is a great choice. Using the command below, you can crop the video to 1920x1080 without re-encoding, ensuring no quality loss:

ffmpeg -i "input.mp4" -c copy -bsf:v h264_metadata=crop_bottom=8 "output.mp4"

This method is fast and maintains the original quality. For detailed tasks, you can also try tools like HandBrake or Shutter Encoder.

[Santiago]

Sorry for the mistake.

[Santiago]

I corrected the mistake.

[salini]

Nice, Sounds great.