[Libav-user] Does the image2 demuxer work with a custom AVIOContext?
Hi, I am having problems programmatically extracting metadata like size and pixel format from a dpx image using a custom AVIOContext. Should that work or does the image2 demuxer only work with files even in the single-file case? Or is there something I need to watch out for when using it this way? In my case the call to avformat_open_input fails already. The same code generally works and has been used/tested with a lot of formats for a long time. It just seems to fail on formats that the command line tool opens with the image2 demuxer (I also tried jpg and png). Is this related to not having a file name and if so, is there a way to fix this? Thanks in advance, Robert ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
[Libav-user] Check an address to see if there is any video stream on it or not
I want to read a video stream from a UDP address using libavcodec functions. To do so, I use the following code: char *url = udp://127.0.0.1:1000; AVFormatContext *oc = NULL; avformat_open_input(oc, url, NULL , NULL); If we run this code, then function avformat_open_input starts listening on the given UDP address, and it looks like the program is halted if there is no video stream at the given UDP address. Now, I want to write a code to first check the given UDP address quickly to see whether there is any data on it or not, if there is no data then the program should neglect running avformat_open_input, otherwise it should run this function so that I can avoid the halting situation. Any idea how I can do this? Thanks! ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Check an address to see if there is any video stream on it or not
12.01.2014, 22:23, Hadi hadi.hadiza...@hotmail.com:
I want to read a video stream from a UDP address using libavcodec functions.
To do so, I use the following code:
char *url = udp://127.0.0.1:1000;
AVFormatContext *oc = NULL;
avformat_open_input(oc, url, NULL , NULL);
If we run this code, then function avformat_open_input starts listening on
the given UDP address, and it looks like the program is halted if there is no
video stream at the given UDP address.
Now, I want to write a code to first check the given UDP address quickly to
see whether there is any data on it or not, if there is no data then the
program should neglect running avformat_open_input, otherwise it should run
this function so that I can avoid the halting situation.
Any idea how I can do this? Thanks!
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use interrupt_callback function to unblock avformat_open_input(...);
concept:
time_t check_timestamp;
static int interrupt_cb(void* inputdata)
{
time_t current_timestamp;
current_timestamp = time(0)
if (current_timestamp - check_timestamp = 10)
return true; // interrupt blocked function
else
return false; // NOT interrupt, wait more seconds...
}
...
oc = avformat_allocate_context();
oc-interrupt_callbacl = (AVIOInterruptCB){interrupt_cb, NULL};
checl_timestamp = time(0);
if (avformat_open_input(oc, url, NULL , NULL) 0)
{
// error processing
}
something like that :) if avformat_open_input frezzes more than 10 seconds (in
this example), interrupt_cb will break it execution.
--
С уважением, Евгений Гарифуллин.
e-mail: gri...@yandex.ru
jabber: joffad...@jabber.ufanet.ru
ICQ : 387906261
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Re: [Libav-user] Does the image2 demuxer work with a custom AVIOContext?
Robert Krüger krueger@... writes: I am having problems programmatically extracting metadata like size and pixel format from a dpx image using a custom AVIOContext. Should that work or does the image2 demuxer only work with files even in the single-file case? Contrary to all other demuxers, there is no auto-detection for image2, so (without looking at the actual code, sorry if it actually works differently) you have to either set demuxer and decoder or demuxer and a file name suffix. Hope that helps, Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Does the image2 demuxer work with a custom AVIOContext?
On Sun, Jan 12, 2014 at 4:49 PM, Robert Krüger krue...@lesspain.de wrote: Hi, I am having problems programmatically extracting metadata like size and pixel format from a dpx image using a custom AVIOContext. Should that work or does the image2 demuxer only work with files even in the single-file case? Or is there something I need to watch out for when using it this way? In my case the call to avformat_open_input fails already. The same code generally works and has been used/tested with a lot of formats for a long time. It just seems to fail on formats that the command line tool opens with the image2 demuxer (I also tried jpg and png). Is this related to not having a file name and if so, is there a way to fix this? image2 requires to directly access the files itself. There is also a image2pipe, which can read the data from a avio context, but in my experience it also didn't work properly because its designed for a pipe scenario where it doesn't know the file size, and therefor reads kinda blindly. Now for custom IO that knows the size, but just wants to deliver the data through its own IO functions, neither seem to work properly as of today. - Hendrik ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Check an address to see if there is any video stream on it or not
Thanks for the response, it works! :) I was thinking to put such a code within
a thread. Whenever avformat_open_input finds a stream at the given address,
then the thread can be terminated. In the meantime, the program can do other
stuffs. But do you know how I can make a thread with libavcodec functions?
From: gri...@yandex.ru
To: libav-user@ffmpeg.org
Date: Sun, 12 Jan 2014 22:38:51 +0600
Subject: Re: [Libav-user] Check an address to see if there is any video
stream on it or not
12.01.2014, 22:23, Hadi hadi.hadiza...@hotmail.com:
I want to read a video stream from a UDP address using libavcodec functions.
To do so, I use the following code:
char *url = udp://127.0.0.1:1000;
AVFormatContext *oc = NULL;
avformat_open_input(oc, url, NULL , NULL);
If we run this code, then function avformat_open_input starts listening on
the given UDP address, and it looks like the program is halted if there is
no video stream at the given UDP address.
Now, I want to write a code to first check the given UDP address quickly to
see whether there is any data on it or not, if there is no data then the
program should neglect running avformat_open_input, otherwise it should
run this function so that I can avoid the halting situation.
Any idea how I can do this? Thanks!
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use interrupt_callback function to unblock avformat_open_input(...);
concept:
time_t check_timestamp;
static int interrupt_cb(void* inputdata)
{
time_t current_timestamp;
current_timestamp = time(0)
if (current_timestamp - check_timestamp= 10)
return true; // interrupt blocked function
else
return false; // NOT interrupt, wait more seconds...
}
...
oc = avformat_allocate_context();
oc-interrupt_callbacl = (AVIOInterruptCB){interrupt_cb, NULL};
checl_timestamp = time(0);
if (avformat_open_input(oc, url, NULL , NULL) 0)
{
// error processing
}
something like that :) if avformat_open_input frezzes more than 10 seconds
(in this example), interrupt_cb will break it execution.
--
С уважением, Евгений Гарифуллин.
e-mail: gri...@yandex.ru
jabber: joffad...@jabber.ufanet.ru
ICQ : 387906261
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Re: [Libav-user] Check an address to see if there is any video stream on it or not
Thanks for the response, it works! :) I was thinking to put such a code within a thread. Whenever avformat_open_input finds a stream at the given address, then the thread can be terminated. In the meantime, the program can do other stuffs. But do you know how I can make a thread with libavcodec functions? -- View this message in context: http://libav-users.943685.n4.nabble.com/Libav-user-Check-an-address-to-see-if-there-is-any-video-stream-on-it-or-not-tp4659115p4659119.html Sent from the libav-users mailing list archive at Nabble.com. ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
[Libav-user] ffmpeg on android
Hi guys,
I am trying to do a stream player in android but I need to read a array of
bytes and then decode every packet of array of bytes. In the end started to
make my AAC decoder work with the ffmpeg example of decoder. But I ran into
the same problem of this guy:
http://stackoverflow.com/questions/13499480/decode-aac-to-pcm-with-ffmpeg-on-android
But the decoder does not work. I am receiving a error as follows:
TNS filter order %d is greater than maximum %d.
Error while decoding: -1
If I use the ffmpeg to decode it works fine.
ffmpeg -i audio.mp4 audio.wav
Environment:
ffmpeg 1.2
Android ndkr9b
Follows my source code:
AVCodec *codec;
AVCodecContext *c= NULL;
int len;
FILE *f, *outfile;
uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
AVPacket avpkt;
AVFrame *decoded_frame = NULL;
av_log_set_callback(my_ffmpeg_log);
av_init_packet(avpkt);
printf(Decode audio file %s to %s\n, filename, outfilename);
/* find the mpeg audio decoder */
codec = avcodec_find_decoder(AV_CODEC_ID_AAC);
if (!codec) {
LOGV(Codec not found\n);
return;
}
c = avcodec_alloc_context3(codec);
c-channels = 2;
c-sample_rate = 48000;
if (!c) {
LOGV(Could not allocate audio codec context\n);
return;
}
/* open it */
if (avcodec_open2(c, codec, NULL) 0) {
LOGV(Could not open codec\n);
return;
}
f = fopen(filename, rb);
if (!f) {
LOGV(Could not open %s\n, filename);
return;
}
outfile = fopen(outfilename, wb);
if (!outfile) {
av_free(c);
return;
}
/* decode until eof */
avpkt.data = inbuf;
avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
while (avpkt.size 0) {
int got_frame = 0;
if (!decoded_frame) {
if (!(decoded_frame = avcodec_alloc_frame())) {
LOGV(Could not allocate audio frame\n);
return;
}
} else
avcodec_get_frame_defaults(decoded_frame);
len = avcodec_decode_audio4(c, decoded_frame, got_frame, avpkt);
if (len 0) {
LOGV(Error while decoding: %d\n, len);
return;
}
if (got_frame) {
/* if a frame has been decoded, output it */
int data_size = av_samples_get_buffer_size(NULL, c-channels,
decoded_frame-nb_samples,
c-sample_fmt, 1);
fwrite(decoded_frame-data[0], 1, data_size, outfile);
}
avpkt.size -= len;
avpkt.data += len;
avpkt.dts =
avpkt.pts = AV_NOPTS_VALUE;
if (avpkt.size AUDIO_REFILL_THRESH) {
/* Refill the input buffer, to avoid trying to decode
* incomplete frames. Instead of this, one could also use
* a parser, or use a proper container format through
* libavformat. */
memmove(inbuf, avpkt.data, avpkt.size);
avpkt.data = inbuf;
len = fread(avpkt.data + avpkt.size, 1,
AUDIO_INBUF_SIZE - avpkt.size, f);
if (len 0)
avpkt.size += len;
}
}
fclose(outfile);
fclose(f);
avcodec_close(c);
av_free(c);
avcodec_free_frame(decoded_frame);
--
*Atenciosamente, Marcelo Paes Rech.*
E-mail: marcelopaesr...@gmail.com
Blog: http://marcelopaesrech.blogspot.com
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Re: [Libav-user] Does the image2 demuxer work with a custom AVIOContext?
Hendrik Leppkes h.leppkes@... writes: image2 requires to directly access the files itself. Thank you for correcting me! There is also a image2pipe, which can read the data from a avio context, but in my experience it also didn't work properly because its designed for a pipe scenario where it doesn't know the file size, and therefor reads kinda blindly. Could you elaborate a little on the shortcomings of image2pipe? I seem to remember that it is used often. Or do you just mean that too many parsers are missing? Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Does the image2 demuxer work with a custom AVIOContext?
On Sun, Jan 12, 2014 at 8:02 PM, Carl Eugen Hoyos ceho...@ag.or.at wrote: Hendrik Leppkes h.leppkes@... writes: image2 requires to directly access the files itself. Thank you for correcting me! There is also a image2pipe, which can read the data from a avio context, but in my experience it also didn't work properly because its designed for a pipe scenario where it doesn't know the file size, and therefor reads kinda blindly. Could you elaborate a little on the shortcomings of image2pipe? I seem to remember that it is used often. Or do you just mean that too many parsers are missing? Yeah it only works on img formats which have a parser to re-assemble full images, so its use is a bit limited. On the other hand, you can actually use it to pipe several images in one command into it (if you have a parser), so both use-cases can be useful i suppose. - Hendrik ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Does the image2 demuxer work with a custom AVIOContext?
Hendrik Leppkes h.leppkes@... writes: Yeah it only works on img formats which have a parser to re-assemble full images, so its use is a bit limited. Note that I (?) implemented -frame_size for image formats with constant frame size. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] ffmpeg on android
Marcelo, have you initialized the ffmpeg using av_register_all()?
Also, when building the ffmpeg, have you included encoding/decoding/
parsing support for aac?
Sylvio
Em 12/01/2014 16:18, Marcelo Paes Rech marcelopaesr...@gmail.com
escreveu:
Hi guys,
I am trying to do a stream player in android but I need to read a array of
bytes and then decode every packet of array of bytes. In the end started to
make my AAC decoder work with the ffmpeg example of decoder. But I ran into
the same problem of this guy:
http://stackoverflow.com/questions/13499480/decode-aac-to-pcm-with-ffmpeg-on-android
But the decoder does not work. I am receiving a error as follows:
TNS filter order %d is greater than maximum %d.
Error while decoding: -1
If I use the ffmpeg to decode it works fine.
ffmpeg -i audio.mp4 audio.wav
Environment:
ffmpeg 1.2
Android ndkr9b
Follows my source code:
AVCodec *codec;
AVCodecContext *c= NULL;
int len;
FILE *f, *outfile;
uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
AVPacket avpkt;
AVFrame *decoded_frame = NULL;
av_log_set_callback(my_ffmpeg_log);
av_init_packet(avpkt);
printf(Decode audio file %s to %s\n, filename, outfilename);
/* find the mpeg audio decoder */
codec = avcodec_find_decoder(AV_CODEC_ID_AAC);
if (!codec) {
LOGV(Codec not found\n);
return;
}
c = avcodec_alloc_context3(codec);
c-channels = 2;
c-sample_rate = 48000;
if (!c) {
LOGV(Could not allocate audio codec context\n);
return;
}
/* open it */
if (avcodec_open2(c, codec, NULL) 0) {
LOGV(Could not open codec\n);
return;
}
f = fopen(filename, rb);
if (!f) {
LOGV(Could not open %s\n, filename);
return;
}
outfile = fopen(outfilename, wb);
if (!outfile) {
av_free(c);
return;
}
/* decode until eof */
avpkt.data = inbuf;
avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
while (avpkt.size 0) {
int got_frame = 0;
if (!decoded_frame) {
if (!(decoded_frame = avcodec_alloc_frame())) {
LOGV(Could not allocate audio frame\n);
return;
}
} else
avcodec_get_frame_defaults(decoded_frame);
len = avcodec_decode_audio4(c, decoded_frame, got_frame, avpkt);
if (len 0) {
LOGV(Error while decoding: %d\n, len);
return;
}
if (got_frame) {
/* if a frame has been decoded, output it */
int data_size = av_samples_get_buffer_size(NULL, c-channels,
decoded_frame-nb_samples,
c-sample_fmt, 1);
fwrite(decoded_frame-data[0], 1, data_size, outfile);
}
avpkt.size -= len;
avpkt.data += len;
avpkt.dts =
avpkt.pts = AV_NOPTS_VALUE;
if (avpkt.size AUDIO_REFILL_THRESH) {
/* Refill the input buffer, to avoid trying to decode
* incomplete frames. Instead of this, one could also use
* a parser, or use a proper container format through
* libavformat. */
memmove(inbuf, avpkt.data, avpkt.size);
avpkt.data = inbuf;
len = fread(avpkt.data + avpkt.size, 1,
AUDIO_INBUF_SIZE - avpkt.size, f);
if (len 0)
avpkt.size += len;
}
}
fclose(outfile);
fclose(f);
avcodec_close(c);
av_free(c);
avcodec_free_frame(decoded_frame);
--
*Atenciosamente, Marcelo Paes Rech.*
E-mail: marcelopaesr...@gmail.com
Blog: http://marcelopaesrech.blogspot.com
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