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Autres articles (48)
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Les vidéos
21 avril 2011, parComme les documents de type "audio", Mediaspip affiche dans la mesure du possible les vidéos grâce à la balise html5 .
Un des inconvénients de cette balise est qu’elle n’est pas reconnue correctement par certains navigateurs (Internet Explorer pour ne pas le nommer) et que chaque navigateur ne gère en natif que certains formats de vidéos.
Son avantage principal quant à lui est de bénéficier de la prise en charge native de vidéos dans les navigateur et donc de se passer de l’utilisation de Flash et (...) -
La file d’attente de SPIPmotion
28 novembre 2010, parUne file d’attente stockée dans la base de donnée
Lors de son installation, SPIPmotion crée une nouvelle table dans la base de donnée intitulée spip_spipmotion_attentes.
Cette nouvelle table est constituée des champs suivants : id_spipmotion_attente, l’identifiant numérique unique de la tâche à traiter ; id_document, l’identifiant numérique du document original à encoder ; id_objet l’identifiant unique de l’objet auquel le document encodé devra être attaché automatiquement ; objet, le type d’objet auquel (...) -
Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
Sur d’autres sites (6086)
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Channel mapping in FFmpeg conversion of Dolby 7.1 mlp file to 8 channel wav file [closed]
21 avril 2024, par Stan DuncanI have a file with 7.1 audio with the following channel mapping (viewed using MediaInfo) :
L R C LFE Ls Rs Lb Rb

I want to convert it to an 8 channel riff64 wave file, so I'm using the following command :


ffmpeg.exe -i "input.mlp" -rf64 auto -c:a pcm_f32le "output.wav"

When I do this, the channel mapping in output.wav changes to (viewed using MediaInfo) :
L R C LFE Lb Rb Ls Rs

I'm not sure if this is just a label that gets slapped on there, or if it actually changes the channel positions (i.e., rear surround come out of side surround speakers and vice versa).


Is there a better command I should be using to ensure that the channel mapping is not altered ?


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FFMPEG Corrupt output remuxing MP4 (Using API in C) -First file OK, 2nd file onwards is not
25 janvier, par RichardPI have a simple application written in C - it takes the video from a RTSP camera and just writes to disk in 1 minute segments. The first file created works fine, plays on anlmost anything. The Second file does not play. Programatically, The trace shows they are the same code flows, but I cant seem to find where the problem is to allow the 2nd file to be play exactly the same as the first.


There are frames in the 2nd file but they are random. The second file is created EXACTLY the same way as the first.


Any help from a guru would be greatly appreciated.


EDIT : FIX - The output duration needs to be set before the trailer is written.


int actual_duration = (int)difftime(time(NULL), start_time);

for (int i = 0; i < output_ctx->nb_streams; i++) {
 output_ctx->streams[i]->duration = actual_duration * AV_TIME_BASE;
}

output_ctx->duration = actual_duration * AV_TIME_BASE;
printf("DURATION = %d\r\n",output_ctx->duration);

// Set the start_time for the output context
output_ctx->start_time = 0;

av_write_trailer(output_ctx);


Code flow


Open RTSP Stream 
A: Create File n context 
 Remux to file n 
 Wait for minute to change 
 Close File n context 
 increment n Goto A


Makefile


CC = gcc
CFLAGS = -Wall -g
LIBS = -lavformat -lavcodec -lavutil -lavdevice -lswscale -lavfilter -lavutil -lm -lz -lpthread

TARGET = rtsp_remux

all: $(TARGET)

$(TARGET): rtsp_remux.o
 $(CC) -o $(TARGET) rtsp_remux.o $(LIBS)

rtsp_remux.o: rtsp_remux.c
 $(CC) $(CFLAGS) -c rtsp_remux.c

clean:
 rm -f $(TARGET) rtsp_remux.o

.PHONY: all clean


rtsp_remux.c

#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>time.h>
#include 
#include 

#define OUTPUT_PREFIX "output"
#define OUTPUT_EXTENSION ".mp4"
#define MAX_FILES 4

int main(int argc, char *argv[]) {
 if (argc < 2) {
 fprintf(stderr, "Usage: %s <rtsp url="url">\n", argv[0]);
 return -1;
 }

 const char *rtsp_url = argv[1];
 AVFormatContext *input_ctx = NULL, *output_ctx = NULL;
 AVOutputFormat *output_fmt = NULL;
 AVPacket pkt;
 int ret, file_count = 0;
 char output_filename[1024];
 time_t current_time;
 struct tm *timeinfo;
 int rename_lock = 0;

 avformat_network_init();

 if ((ret = avformat_open_input(&input_ctx, rtsp_url, NULL, NULL)) < 0) {
 fprintf(stderr, "Could not open input file '%s'\n", rtsp_url);
 return -1;
 }

 if ((ret = avformat_find_stream_info(input_ctx, NULL)) < 0) {
 fprintf(stderr, "Failed to retrieve input stream information\n");
 return -1;
 }

 av_dump_format(input_ctx, 0, rtsp_url, 0);

 while (file_count < MAX_FILES) {
 snprintf(output_filename, sizeof(output_filename), "%s_%03d%s", OUTPUT_PREFIX, file_count, OUTPUT_EXTENSION);

 if ((ret = avformat_alloc_output_context2(&output_ctx, NULL, NULL, output_filename)) < 0) {
 fprintf(stderr, "Could not create output context\n");
 return -1;
 }

 output_fmt = output_ctx->oformat;

 for (int i = 0; i < input_ctx->nb_streams; i++) {
 AVStream *in_stream = input_ctx->streams[i];
 AVStream *out_stream = avformat_new_stream(output_ctx, NULL);
 if (!out_stream) {
 fprintf(stderr, "Failed allocating output stream\n");
 return -1;
 }

 if ((ret = avcodec_parameters_copy(out_stream->codecpar, in_stream->codecpar)) < 0) {
 fprintf(stderr, "Failed to copy codec parameters\n");
 return -1;
 }
 out_stream->codecpar->codec_tag = 0;
 }

 if (!(output_fmt->flags & AVFMT_NOFILE)) {
 if ((ret = avio_open(&output_ctx->pb, output_filename, AVIO_FLAG_WRITE)) < 0) {
 fprintf(stderr, "Could not open output file '%s'\n", output_filename);
 return -1;
 }
 }

 if ((ret = avformat_write_header(output_ctx, NULL)) < 0) {
 fprintf(stderr, "Error occurred when opening output file\n");
 return -1;
 }

 while (1) {
 current_time = time(NULL);
 timeinfo = localtime(&current_time);

 if (timeinfo->tm_sec == 0 && !rename_lock) {
 rename_lock = 1;
 break;
 } else if (timeinfo->tm_sec != 0) {
 rename_lock = 0;
 }

 if ((ret = av_read_frame(input_ctx, &pkt)) < 0)
 break;

 AVStream *in_stream = input_ctx->streams[pkt.stream_index];
 AVStream *out_stream = output_ctx->streams[pkt.stream_index];

 pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
 pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
 pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
 pkt.pos = -1;

 if ((ret = av_interleaved_write_frame(output_ctx, &pkt)) < 0) {
 fprintf(stderr, "Error muxing packet\n");
 break;
 }

 av_packet_unref(&pkt);
 }

 av_write_trailer(output_ctx);

 if (!(output_fmt->flags & AVFMT_NOFILE))
 avio_closep(&output_ctx->pb);

 avformat_free_context(output_ctx);

 file_count++;
 }

 avformat_close_input(&input_ctx);
 avformat_network_deinit();

 return 0;
}
</rtsp>

I have tried changing to pointers, freeing and different things. I was expecting the 2nd file created to behave identically to the first.


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How to convert .srt file into ttml based xml subtitle file using ffmpeg ?
25 août 2023, par geo-freakI have an .srt subtitle file. I want to convert it into .ttml format(or xml) using ffmpeg command. I tried using traditional way to convert this. But ffmpeg throwing an error. Is there any way to convert this in Linux platform ? Or any other command line applications do this conversion ?


Below is the command I tried.


ffmpeg -i my_srt.srt -y srt-to-xml.xml -v verbose

ffmpeg version 4.2.4-1ubuntu0.1 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, srt, from 'my_srt.srt':
Duration: N/A, bitrate: N/A
 Stream #0:0: Subtitle: subrip
Output #0, webm_dash_manifest, to 'srt-to-xml.xml':
Output file #0 does not contain any stream
[AVIOContext @ 0x5614924ef500] Statistics: 22267 bytes read, 0 seeks


I even tried like below.


ffmpeg -i my_srt.srt -y srt_to_ttml.ttml


It didn't work too.


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