ffmpeg 3gp encoding help

[hss2293]

I am using the following command to convert video in 3gp

ffmpeg -i video.mp4 -vcodec mpeg4 -s 320x240 -b 170 -aspect 4:3 -acodec aac -ab 32k -ar 44100 output.3gp

The video quality is not so good.. It is rough at many parts..
I have one another 3gp file which has same bitrate but its quality is very good.. Its not rough enough..
Is there any way to increase 3gp quality..

[Baldrick]

Post the details from the 3gp with the very good quality. Use mediainfo, open 3gp, view->text and copy everything.



And how good is the video.mp4 quality? If it's low it will get even worse when using so low bitrate.

[hss2293]

The video.mp4 file is HD 720p i have uploaded the sample of 3gp video which has high quality

[hss2293]

Mediainfo of 3gp file having good quality

Format                                   : MPEG-4
Format profile                           : 3GPP Media Release 4
Codec ID                                 : 3gp4
File size                                : 2.99 MiB
Duration                                 : 2mn 0s
Overall bit rate mode                    : Variable
Overall bit rate                         : 209 Kbps

Video
ID                                       : 1
Format                                   : MPEG-4 Visual
Format profile                           : Simple@L1
Format settings, BVOP                    : No
Format settings, QPel                    : No
Format settings, GMC                     : No warppoints
Format settings, Matrix                  : Default (H.263)
Codec ID                                 : 20
Duration                                 : 1mn 56s
Bit rate                                 : 177 Kbps
Width                                    : 320 pixels
Height                                   : 240 pixels
Display aspect ratio                     : 3:2
Original display aspect ratio            : 4:3
Frame rate mode                          : Constant
Frame rate                               : 23.976 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Compression mode                         : Lossy
Bits/(Pixel*Frame)                       : 0.096
Stream size                              : 2.47 MiB (83%)
Writing library                          : Lavc55.12.100
Language                                 : English

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 2mn 0s
Bit rate mode                            : Variable
Bit rate                                 : 32.0 Kbps
Channel(s)                               : 2 channels
Original Channel count                   : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 44.1 KHz
Compression mode                         : Lossy
Stream size                              : 469 KiB (15%)

[Selur]

Is there any way to increase 3gp quality..

using xvid and 2pass encoding

[hss2293]

Is there any way to increase 3gp quality..

using xvid and 2pass encoding

In 2 pass we have to keep bitrate high and it will increase video size.

[Selur]

In 2 pass we have to keep bitrate high and it will increase video size.

Why do you have to choose a higher bit rate?

Also MediaInfo states:
Width : 320 pixels
Height : 240 pixels
23.976 fps
and
Simple@L1
but Simple@L1 doesn't allow such a high resolution, see: http://en.wikipedia.org/wiki/MPEG-4

also when you aim for such low resolutions and bitrates you often can get away with halving the frame rate.