Output frame rate is not same as input frame rate and option -r does not seem to work

[saialluru]

ffmpeg -r 25 -i 20140806_172538.avi -b:v 12288k -f mpegts udp://192.168.0.20:9001?pkt_size=188 -preset placebo -r 25
ffmpeg version 2.2.4 Copyright (c) 2000-2014 the FFmpeg developers

built on Jun 27 2014 09:57:37 with llvm-gcc 4.2.1 (LLVM build 2336.11.00)
configuration: --prefix=/Volumes/Ramdisk/sw --enable-gpl --enable-pthreads --enable-version3 --enable-libspeex --enable-libvpx --disable-decoder=libvpx --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-libgsm --enable-libvidstab --enable-libx265 --arch=x86_64 --enable-runtime-cpudetect
libavutil 52. 66.100 / 52. 66.100
libavcodec 55. 52.102 / 55. 52.102
libavformat 55. 33.100 / 55. 33.100
libavdevice 55. 10.100 / 55. 10.100
libavfilter 4. 2.100 / 4. 2.100
libswscale 2. 5.102 / 2. 5.102
libswresample 0. 18.100 / 0. 18.100
libpostproc 52. 3.100 / 52. 3.100

Trailing options were found on the commandline.
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, avi, from '20140806_172538.avi':

Duration: 00:02:04.84, start: 0.000000, bitrate: 3888 kb/s

Stream #0:0: Video: h264 (High) (H264 / 0x34363248), yuv420p, 1920x1080, 25 fps, 25 tbr, 25 tbn, 50 tbc
Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 8000 Hz, mono, s16, 128 kb/s

Output #0, mpegts, to 'udp://192.168.0.20:9001?pkt_size=188':

Metadata:

encoder : Lavf55.33.100
Stream #0:0: Video: mpeg2video, yuv420p, 1920x1080, q=2-31, 12288 kb/s, 90k tbn, 25 tbc
Stream #0:1: Audio: mp2, 16000 Hz, mono, s16, 128 kb/s

Stream mapping:

Stream #0:0 -> #0:0 (h264 -> mpeg2video)
Stream #0:1 -> #0:1 (pcm_s16le -> mp2)

Press [q] to stop, ? for help
frame= 3121 fps= 83 q=3.5 Lsize= 204741kB time=00:02:05.75 bitrate=13337.4kbits/s
video:187505kB audio:1965kB subtitle:0 data:0 global headers:0kB muxing overhead 8.059494%

It is streaming at 83 sometimes 90 fps while the source is 25 fps

[Cigaes]

ffmpeg always outputs as fast as it can by default. The timestamps embedded in the output stream are correct, though. Use the -re option to make ffmpeg slow down to try and match the content's frame rate.