November 2003 - MPlayer-dev-eng - lists.mplayerhq.hu

Synchronization of players in LAN
by J.A. Gutierrez 18 Jun '08

18 Jun '08

Hello I'm trying to synchronise several players running on several computers connected to a dedicated 10/100 Ethernet switch. Each one reads a different movie (video only) from its internal hard disk, and resolution will be 768x576. I'm thinking of a simple solution: - Add some code at mplayer startup so it will wait for an UDP broadcast packet (sent by a central master in the LAN). This way all the players would start at the same time. - Use NTP to keep in sync all the computers' clocks, and trust mplayer's rtc synchronisation feature. With this simple setup, could we be sure all the players would keep the synchronisation? Or should the master computer track them all and take control on their speeds? How difficult would be to add code so all the player synchronise using the LAN? Or should I use some external clock connected to all serial ports? Or use a totally different approach? Thanks. -- finger spd(a)shiva.cps.unizar.es for PGP / .mailcap tip of the day: / La vida es una carcel application/ms-tnef; cat '%s' > /dev/null / con las puertas abiertas text/x-vcard; cat '%s' > /dev/null / (A. Calamaro)

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[PATCH] ffw-av - interactive fastforward/slow with audio speed adjust (1st draft)
by Steven Mueller 19 Oct '04

19 Oct '04

Hello, Here is a first attempt at a live interactive fast/slow-forward patch that also modifies the speed of sound playback to (approximately) match the video playback rate. It applies cleanly against current cvs as of the time of writing. It's still rather quirky, owing to my not quite understanding the A-V sync structure and the various audio output layers, and possibly due to limitations in the demuxers as postulated below. I've implemented sound output reinitialization to scale the sample rate, but I'm not sure if what I did was kosher, so I'd appreciate a few eyes on it. The patch adds three new mappable commands for input.conf: speed_set float set the playback rate. 1.0 is normal speed speed_mult float multiply the current speed (positive only) speed_incr float increment the current speed (can be negative) Default keyboard mappings: [, ] Decrease/increase the speed by a small factor (= 1.1) {, } Decrease/increase the speed by a large factor (= 2) Backspace Reset the speed to normal The playback_speed is implemented using the infrastructure for the -speed commandline argument, so the allowable range is .01 to 100. Caveats: 1. Not all sound drivers can accelerate the sound speed past a certain sample rate. Some also hold back the video speed. (For example, alsa9 on my system on certain divx files limits the playback rate to 1.0. However, the OSS emulation of my alsa driver does not suffer the same problem... The divx5.0 files from www.redvsblue.com exhibit this behavior, for example.) One can sort of work around this by specifying "-aop list=resample" on the commandline. This causes the speed modifications to apply to the resample audio plugin, and therefore uses more cpu but can have a wider range of possibilities. It also will not limit the video playback rate as far as I've seen. However (this is a big however!) increasing or decreasing the speed too much can cause the A-V sync to go very out of control. Using "-mc 10" can slightly alleviate this problem, but only to a certain extent (about 5x on my 1.3 ghz tbird). Every time I change the speed, alsa9 reports the same samplerate (48000) until I increase the speed too high (~10x), at which point the debug message suddenly shows the resampling being applied to the alsa chain directly and the sound reverts to 1x speed. Of course, this problem also happens with the -speed commandline option. 2. Changing the speed rate can cause minor jumps in the video file. On some files (notably quicktime and wmv), the movie is sped up for a short moment so that you miss a half second or so, regardless of whether you're slowing way down or speeding way up. Note that this phenomenon occurs when pausing and resuming in normal speed playback as well, so I'm thinking this could be limitations with the individual codecs' demuxers rather than with the way I reinitialize the sound. 3. Using a very low speed can make mplayer very unresponsive, since mplayer can only accept one command per rendered frame... 4. The speed display at the end of the status display line only appears when both audio and video are being played, but I'm not sure this field is good anyway since it easily puts the line length at more than 80 characters. Regardless, I can easily add it to the audio/video-only lines if anyone is interested. Another option would be to make it display the speed only when it is not 1x (which I kinda like best, actually...) TODO: * Add an OSD to display the new speed for a short while whenever it's changed (and the osd level is high enough) * Display speed on status line iff playback_speed != 1.0 +/- delta * Add an option to partially mute the sound volume a given amount whenever the speed is not exactly 1.0x (or maybe there should be some (configurable?) tolerance?) * Write proper documentation (changes to manpage and DOC files) * Examine the play loop more closely to determine whether the skips of accelerated playback in certain videos (as described above) can be avoided, and perhaps get the audio to more instantaneously sync, too... Anyway, I hope people find it useful, and I hope to get it to a point where it can be included in mplayer. After writing the bulk of the patch, I discovered the following thread in the archives, so I'm hoping there's still a bit of interest: http://mplayerhq.hu/pipermail/mplayer-dev-eng/2003-February/015835.html Thanks, Steve PS - Sorry for the excessively long description. :) -- Steven Mueller diffusor(a)ugcs.caltech.edu

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Patch: vo_shm - simple embedding vo
by Flemming Frandsen 13 Oct '04

13 Oct '04

I have a project where I want to play a movie as a texture in OpenGL in realtime, so naturally I turned to MPlayer, I copy+pasted from vo_tga and created a video out plugin that outputs frames to shared memory. It doesn't use any locking, so it should be low-overhead for both mplayer and the consumer, but that also means that the consumer must have it's own framerate (which my opengl application does have). It works by having the consumer set up a shared memory segment that holds the shmids of two frame buffers, vo_shm writes to the framebuffer with the lowest frame number and the consumer reads from the framebuffer with the higest frame number, that way they don't step on eachothers toes. I've tested it and it works quite nicely, so here is the patch if you'd like to include it: http://dion.swamp.dk/dl/mplayer-1.0pre1-shm1.diff.gz Any comments? -- Regards Flemming Frandsen - http://dion.swamp.dk PartyTicket.Net co founder & Yet Another Perl Hacker

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Unable to pass options to vo hardware equalizer via the command line
by Oleg I. Vdovikin 17 Jul '04

17 Jul '04

Hi, this posting relates to the problem, stated & patched in my previous letter. Current flow inside the mplayer does not allow to set hardware equalizer options via the command line. The problem is due to the fact, that mplayer calls equalizer (dec_video::set_colors) BEFORE the vo initialization. So, vf_vo::control checks the init status & rejects the call. The similar checks are done by vosub_vidix::vidix_control. Unfortunatly I've not enough knowledge of the flow inside the mplayer, so I can't do the right patch. For now I've just commented out the initializtion checks both in vf_vo & vosub_vidix, so it now works for my setup (with vidix_control patch... Any thoughts? Regards, Oleg.

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[PATCH] xml docs fix and mpst:// docs
by Alban Bedel 14 Jul '04

14 Jul '04

Hi, I wrote a little doc for the mpst:// stuff. I also fixed the tv examples and found a little mistake in the edl docs. The mpst docs are not in the patch as i don't have DocBook installed so i can't chacek that everything is ok. Albeu

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[PATCH] (main) configure script output neat-ening
by Alex Sisson 12 Jul '04

12 Jul '04

Hi, Just a little patch that just seperates all the checks into sections (video inputs, audio, codecs, etc) to make its output a bit clearer when youre trying to check if a certain thing is being detected. (yes i know theres the summary bit at the bottom but i dont like that as much :-)) Basically just added some echos, moved the video+audio checks above the video checks, and because there were a few things (zlib etc) in the wrong place have moved them down to the 'other' section. Alex Sisson ________________________________________________________________________ Want to chat instantly with your online friends? Get the FREE Yahoo! Messenger http://uk.messenger.yahoo.com/

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[PATCH] vo_gl2.c - glClear every frame in fullscreen mode
by Timo Kanera 03 May '04

03 May '04

Hi, the attached patch modifies vo_gl2.c to perform a glClear(GL_COLOR_BUFFER_BIT) for every frame when in fullscreen mode. This seems to be needed because of the way glXSwapBuffers works. From the glXSwapBuffers manpage: The contents of the back buffer become undefined after a swap. Note that this applies to pixel buffers as well as windows. so long, Timo -- Timo Kanera <timo(a)kanera.de> . GPG Key-ID: 1024D/30CDB412

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mplayer G2
by elcabesa 20 Feb '04

20 Feb '04

any news from mplayer g2? is thee a html page, something to download??

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build error
by Kevin DeKorte 19 Feb '04

19 Feb '04

I have checked out a fresh copy of mplayer, and linked in libavcodec and then ran configure and make and I keep getting this error. I'm running on RedHat 9 and was able to compile a working mplayer a few days ago. ./configure --enable-gui --enable-freetype --with-reallibdir=/home/kdekorte/cvs/mplayer/rp9codecs --enable-live --with-livelibdir=/home/kdekorte/cvs/mplayer/live mplayer.o(.data+0x2e24): undefined reference to `pp_help' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0xdb): In function `open': : undefined reference to `pp_get_mode_by_name_and_quality' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0x238): In function `config': : undefined reference to `pp_get_context' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0x27f): In function `config': : undefined reference to `pp_free_context' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0x2df): In function `uninit': : undefined reference to `pp_free_mode' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0x503): In function `put_image': : undefined reference to `pp_postprocess' libmpcodecs/libmpcodecs.a(vf_pp.o)(.text+0x2d7): In function `uninit': : undefined reference to `pp_free_context' collect2: ld returned 1 exit status make: *** [mplayer] Error 1 Kevin

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ALSA 1.x patch needs a small patch if BUFFERTIME is used
by Richard Chan 17 Feb '04

17 Feb '04

Hi, if BUFFERTIME is used a small fix is needed due to the slight change in ALSA APIs. Return values are now just error codes; parameter return values are in pointer arguments. For your kind consideration. BTW (I am new to this ) why is SET_CHUNKSIZE preferred to BUFFERTIME? I'm getting alsa_init: unable to set periodsize always when trying to play back 44.1kHz on a via82xx (fixed 48kHz). /usr/src/mplayer/main> diff -u libao2/ao_alsa1x.c ../main2/libao2/ao_alsa1x.c --- libao2/ao_alsa1x.c 2003-11-23 10:05:06.521940544 +0800 +++ ../main2/libao2/ao_alsa1x.c 2003-11-22 22:16:42.000000000 +0800 @@ -76,8 +76,9 @@ #define ALSA_DEVICE_SIZE 48 -#undef BUFFERTIME -#define SET_CHUNKSIZE +//#undef BUFFERTIME +#define BUFFERTIME +//#define SET_CHUNKSIZE #undef USE_POLL @@ -526,7 +527,7 @@ printf("alsa-init: error set block-mode %s\n", snd_strerror(err)); } else if (verbose>0) { - printf("alsa-init: pcm opend in %s\n", str_block_mode); + printf("alsa-init: pcm opened in %s\n", str_block_mode); } snd_pcm_hw_params_alloca(&alsa_hwparams); @@ -597,16 +598,20 @@ #ifdef BUFFERTIME { int alsa_buffer_time = 500000; /* original 60 */ + int alsa_period_time; + int dir = 0; - if ((err = snd_pcm_hw_params_set_buffer_time_near(alsa_handler, alsa_hwparams, alsa_buffer_time, 0)) < 0) + alsa_period_time = alsa_buffer_time/4; + if ((err = snd_pcm_hw_params_set_buffer_time_near(alsa_handler, alsa_hwparams, &alsa_buffer_time, &dir)) < 0) { printf("alsa-init: unable to set buffer time near: %s\n", snd_strerror(err)); return(0); - } else - alsa_buffer_time = err; + } else { + // alsa_buffer_time = err; + } - if ((err = snd_pcm_hw_params_set_period_time_near(alsa_handler, alsa_hwparams, alsa_buffer_time/4, 0)) < 0) + if ((err = snd_pcm_hw_params_set_period_time_near(alsa_handler, alsa_hwparams, &alsa_period_time, &dir)) < 0) /* original: alsa_buffer_time/ao_data.bps */ { printf("alsa-init: unable to set period time: %s\n", @@ -614,7 +619,7 @@ return(0); } if (verbose>0) - printf("alsa-init: buffer_time: %d, period_time :%d\n",alsa_buffer_time, err); + printf("alsa-init: buffer_time: %d, period_time :%d\n",alsa_buffer_time, alsa_period_time); } #endif

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