Marcus Johnson | 17 Sep 01:10 2014
Picon

Decoding audio?

I'm writing a program to demux and decode audio with the help of the ffmpeg libraries, I'm to the part where the audio is decoded but I'm not sure which function the decoded audio comes out of?

how do I grab the decoded audio so I can further process it myself?
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Deron | 15 Sep 20:04 2014

iOS video player

Has anyone successfully used libav to build a video player that can play 
720p video on an iPhone/iPad? I've got a test app written that uses 
ffplay as a model and it plays, but the decode rate is in a single digit 
frames per second range. I realize that my code, the ffmpeg build, or 
the wind could be the cause but before I dig into these possibilities 
I'm wondering if such a thing is even possible. I installed the VLC app 
and it was no better, which doesn't give me a warm fuzzy feeling.

Thanks for any guidance,

Deron
Клыков Николай | 15 Sep 15:22 2014
Picon

Calculating DTS PTS H.264

Hello, i'm trying to get h.264 rtp stream and write it to mp4 container via live555+ffmpeg. I can get SPS+PPS params from stream and feed it to ffmpeg decoder, so decoding works fine. But i can't properly write nals to mp4 container. I think, i should detect first and last nals of frame, write them to avpacket and fill dts, pts and duration fields. Please, tell me how can i do that.
------
Klykov Nickolay
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Tuviah Snyder | 14 Sep 00:54 2014
Picon

How do I drop corrupted video frames as a result of network issues

I have an RTSP server running on an iPhone broadcasting H264 over UDP in a local network and I'm using
libavformat, libavcodec to demux it and decode on an application running on the desktop.. For the most
part it works well with a second latency, but every minute or so I see a few packets are late, dropped, not
received at all and therefore I get a corrupt frame with visible macro blocking. 

Is there any way to detect after decode if the decoder did not have enough information to decode a perfect
frame? Don't want AVDecode to try to conceal it, just want to keep feeding in packets to decode, and know if
any information was missing, which was required to decode that particular frame. Because our users would
rather we never display a corrupt frame, since the iPhone source is just one of many being integrated into a
live production (and corrupt frames would lower the overall production value). Instead they want our
desktop app to keep displaying the last good frame, until the next good one comes along.

Best
Tuviah
Marcus Johnson | 13 Sep 19:30 2014
Picon

Sharing input file?

I'm writing a C++ program, and I'm trying to use LibAVCodec to decode audio a user enters into my program, with the aforementioned library.

in my program I've set up InputFile as an ifstream object, that takes input from argv[1], what function do I use to pass this handle to the library?
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Dmitry Adjiev | 13 Sep 19:32 2014
Picon

Qt + swsscale on android

Hello guys!
I have the issue with sws_scale and Qt on android:

Here is my code:

AVFrame *pict = av_frame_alloc();
                avpicture_alloc((AVPicture*) pict, AV_PIX_FMT_RGB24, width, height);
                sws_scale(sws_ctx, const_cast<const u_int8_t** const> (frame->data), frame->linesize, 0, height, pict->data, pict->linesize);
                QImage image(width, height, QImage::Format_RGB888);
                //QImage image(frame->data[0], frame->width, frame->height, QImage::Format_RGB888);

                for (int y = 0; y < height; ++ y)
                    memcpy(image.scanLine(y), frame->data[0] + y * frame->linesize[0], codec->width * 3);


In result Image repeats  3 times, please find attached file
What I do wrong?
--
Regards,
Dmitry
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Ming Zhang | 12 Sep 05:43 2014
Picon

FFmpeg support for libstagefright hardware decoding

Hi, everyone:
I am new to ffmpeg. Recently I am working on project to port ffmpeg to android device.
At the beginning, I compiled ffmpeg to shared libs(.so files) in a very normal way following some guides on Internet, load them into my android app. It works perfectly.
Now I want ffmpeg to use libstagefright to fulfill HW decoding.
The problem is, I can compile the .so libs, but when I launch my app and load those .so libs, there is always a java.lang.UnsatisfiedLinkError:
Cannot load library: reloc_library[1314]: 114 cannot locate '_ZN7android11MediaBufferC1Ej'
I stuck there for a few days. Does anyone encountered any similar problems before? It would be great if someone can give me some hint about this error.

My steps:
1. Compile ffmpeg-2.1.4 souce code to .so shared libs. I use the build_libstagefright script to do this, and make some modification based on some guides from Internet. The script is on the attachment.
2. Copy the compiled include and lib directories to my android-ndk-r7/sources/ffmpeg-2.1.4/android/arm directory. The Android.mk under this dir is in the attachment(Android.mk1).
3. Under the jni directory of my android app, the Android.mk and Application.mk files are in the attachment.

I am not sure what else materials you need, if anything is missing, please let me know, I will upload it.
Thank you guys very much!!!
Attachment (ffmpeg.zip): application/zip, 3550 bytes
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Ming Zhang | 12 Sep 01:13 2014
Picon

FFmpeg support for libstagefright hardware decoding

Hi, everyone:
I am new to ffmpeg. Recently I am working on project to port ffmpeg to android device.
At the beginning, I compiled ffmpeg to shared libs(.so files) in a very normal way following some guides on Internet, load them into my android app. It works perfectly.
Now I want ffmpeg to use libstagefright to fulfill HW decoding.
The problem is, I can compile the .so libs, but when I launch my app and load those .so libs, there is always a java.lang.UnsatisfiedLinkError:
Cannot load library: reloc_library[1314]: 114 cannot locate '_ZN7android11MediaBufferC1Ej'
I stuck there for a few days. Does anyone encountered any similar problems before? It would be great if someone can give me some hint about this error.

My steps:
1. Compile ffmpeg-2.1.4 souce code to .so shared libs. I use the build_libstagefright script to do this, and make some modification based on some guides from Internet. The script is on the attachment.
2. Copy the compiled include and lib directories to my android-ndk-r7/sources/ffmpeg-2.1.4/android/arm directory. The Android.mk under this dir is in the attachment(Android.mk1).
3. Under the jni directory of my android app, the Android.mk and Application.mk files are in the attachment.

I am not sure what else materials you need, if anything is missing, please let me know, I will upload it.
Thank you guys very much!!!
Attachment (build_libstagefright.sh): application/x-sh, 6180 bytes
Attachment (Android.mk1): application/octet-stream, 1446 bytes
Attachment (Android.mk2): application/octet-stream, 919 bytes
Attachment (Application.mk): application/octet-stream, 89 bytes
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user
Anthony Clark | 11 Sep 23:16 2014

avio raw yuv

Hey all,

I have a YUV file I created with something like `ffmpeg -i video.mp4 -c:v
rawvideo -pix_fmt yuv420p out.yuv`. I want to use libav* to retrieve video
frames from this raw file. Any clues? So far I just create an
`av_file_map` and get the data that way - it's a little primitive. Does
YUV have a demuxer? Decoder? I couldn't find anything in 2.2.4's source
but maybe I looked at the wrong things.

Oh, I should note that using the `avio_reading.c` example in 2.2.x fails
on `avformat_open_input` - telling me YUV/raw is a little special. Any
help is greatly appreciated!
Gustav González | 11 Sep 22:29 2014
Picon

How to remove header from video file

Hello there,

Right now I have to deal with a little strange requirement:

I need to handle a mp4 video to copy all the binary content from it
but the header. I mean, the new file only must have the frames
section.

Is this possible?

Thanks!
--

-- 
============================
  Gustav Gonzalez
  xtingray@...
============================
Федор | 11 Sep 22:03 2014
Picon

Symbian build

Hi! I try to build FFMPEG static libraries. My environment : WinXP x64, Msys shell, GCC 4.4.1 from Codesourcery for Symbian, self-builded GNU make 4.0 by MS visual studio 2010.

For this I change Rasberry build script. It runs and produce right config.mak and config.h. But when I run make I got error:

$ make
config.mak:5: *** Recursive variable `prefix' references itself (eventually). Stop.
I try:

$ make -d
GNU Make 4.0
Built for Windows32
Copyright (C) 1988-2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
find_and_set_shell() path search set default_shell = D:/Symbian/CSL_Arm_Toolchain/msys/bin/sh.exe
Reading makefiles...
Reading makefile 'Makefile'...
Reading makefile 'config.mak' (search path) (no ~ expansion)...
Reading makefile 'common.mak' (search path) (no ~ expansion)...
Reading makefile 'arch.mak' (search path) (no ~ expansion)...
Reading makefile 'libavdevice/Makefile' (search path) (no ~ expansion)...
Reading makefile 'libavdevice/../config.mak' (search path) (no ~ expansion)...
Reading makefile 'libavdevice/arm/Makefile' (search path) (don't care) (no ~ expansion)...
Reading makefile 'library.mak' (search path) (nconfig.mak:5: ***. Stop.o ~ expansion)...
Reading makefile 'common.mak' (search path) (no ~ expansion)...
Reading makefile 'arch.mak' (search path) (no ~ expansion)...


FFMREG configure script already has Symbian support, I add search path to static and import libraries. Also add some extra static and import libraries. Send my configure and symbian.sh configuration and build script. config.log  - http://pastebin.com/DkfeTK8T , config.mak - http://pastebin.com/2vM2wZir


Always yours, Fedor.
Attachment (ffmpeg-2.3.3.zip): application/zip, 62 KiB
_______________________________________________
Libav-user mailing list
Libav-user@...
http://ffmpeg.org/mailman/listinfo/libav-user

Gmane