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Participer à sa traduction
10 avril 2011Vous pouvez nous aider à améliorer les locutions utilisées dans le logiciel ou à traduire celui-ci dans n’importe qu’elle nouvelle langue permettant sa diffusion à de nouvelles communautés linguistiques.
Pour ce faire, on utilise l’interface de traduction de SPIP où l’ensemble des modules de langue de MediaSPIP sont à disposition. ll vous suffit de vous inscrire sur la liste de discussion des traducteurs pour demander plus d’informations.
Actuellement MediaSPIP n’est disponible qu’en français et (...) -
Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs -
Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir
Sur d’autres sites (12220)
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Unable to encode H264 video using FFMPEG example
4 mai 2020, par Basit AnwerFFMPEG encode example fails to create a H264 video. MPEG1 works fine though.



Pasting the code here as well




 * @file
 * video encoding with libavcodec API example
 *
 * @example encode_video.c
 */
 #include 
 #include 
 #include 
 #include <libavcodec></libavcodec>avcodec.h>
 #include <libavutil></libavutil>opt.h>
 #include <libavutil></libavutil>imgutils.h>
 static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,
 FILE *outfile)
 {
 int ret;
 /* send the frame to the encoder */
 if (frame)
 printf("Send frame %3"PRId64"\n", frame->pts);
 ret = avcodec_send_frame(enc_ctx, frame);
 if (ret < 0) {
 fprintf(stderr, "Error sending a frame for encoding\n");
 exit(1);
 }
 while (ret >= 0) {
 ret = avcodec_receive_packet(enc_ctx, pkt);
 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
 return;
 else if (ret < 0) {
 fprintf(stderr, "Error during encoding\n");
 exit(1);
 }
 printf("Write packet %3"PRId64" (size=%5d)\n", pkt->pts, pkt->size);
 fwrite(pkt->data, 1, pkt->size, outfile);
 av_packet_unref(pkt);
 }
 }

 int main(int argc, char **argv)
 {
 const char *filename, *codec_name;
 const AVCodec *codec;
 AVCodecContext *c= NULL;
 int i, ret, x, y;
 FILE *f;
 AVFrame *frame;
 AVPacket *pkt;
 uint8_t endcode[] = { 0, 0, 1, 0xb7 };
 if (argc <= 2) {
 fprintf(stderr, "Usage: %s <output file="file"> <codec>\n", argv[0]);
 exit(0);
 }
 filename = argv[1];
 codec_name = argv[2];
 /* find the mpeg1video encoder */
 codec = avcodec_find_encoder_by_name(codec_name);
 if (!codec) {
 fprintf(stderr, "Codec '%s' not found\n", codec_name);
 exit(1);
 }
 c = avcodec_alloc_context3(codec);
 if (!c) {
 fprintf(stderr, "Could not allocate video codec context\n");
 exit(1);
 }
 pkt = av_packet_alloc();
 if (!pkt)
 exit(1);
 /* put sample parameters */
 c->bit_rate = 400000;
 /* resolution must be a multiple of two */
 c->width = 352;
 c->height = 288;
 /* frames per second */
 c->time_base = (AVRational){1, 25};
 c->framerate = (AVRational){25, 1};
 /* emit one intra frame every ten frames
 * check frame pict_type before passing frame
 * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
 * then gop_size is ignored and the output of encoder
 * will always be I frame irrespective to gop_size
 */
 c->gop_size = 10;
 c->max_b_frames = 1;
 c->pix_fmt = AV_PIX_FMT_YUV420P;
 if (codec->id == AV_CODEC_ID_H264)
 av_opt_set(c->priv_data, "preset", "slow", 0);
 /* open it */
 ret = avcodec_open2(c, codec, NULL);
 if (ret < 0) {
 fprintf(stderr, "Could not open codec: %s\n", av_err2str(ret));
 exit(1);
 }
 f = fopen(filename, "wb");
 if (!f) {
 fprintf(stderr, "Could not open %s\n", filename);
 exit(1);
 }
 frame = av_frame_alloc();
 if (!frame) {
 fprintf(stderr, "Could not allocate video frame\n");
 exit(1);
 }
 frame->format = c->pix_fmt;
 frame->width = c->width;
 frame->height = c->height;
 ret = av_frame_get_buffer(frame, 32);
 if (ret < 0) {
 fprintf(stderr, "Could not allocate the video frame data\n");
 exit(1);
 }
 /* encode 1 second of video */
 for (i = 0; i < 25; i++) {
 fflush(stdout);
 /* make sure the frame data is writable */
 ret = av_frame_make_writable(frame);
 if (ret < 0)
 exit(1);
 /* prepare a dummy image */
 /* Y */
 for (y = 0; y < c->height; y++) {
 for (x = 0; x < c->width; x++) {
 frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
 }
 }
 /* Cb and Cr */
 for (y = 0; y < c->height/2; y++) {
 for (x = 0; x < c->width/2; x++) {
 frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;
 frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
 }
 }
 frame->pts = i;
 /* encode the image */
 encode(c, frame, pkt, f);
 }
 /* flush the encoder */
 encode(c, NULL, pkt, f);
 /* add sequence end code to have a real MPEG file */
 if (codec->id == AV_CODEC_ID_MPEG1VIDEO || codec->id == AV_CODEC_ID_MPEG2VIDEO)
 fwrite(endcode, 1, sizeof(endcode), f);
 fclose(f);
 avcodec_free_context(&c);
 av_frame_free(&frame);
 av_packet_free(&pkt);
 return 0;
 }
</codec></output>


The code fails at encode call and every
avcodec_receive_packetcall returnsAVERROR(EAGAIN)


What am i missing here ?


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Unable to encode H264 video using FFMPEG example
4 mai 2020, par Basit AnwerFFMPEG encode example fails to create a H264 video. MPEG1 works fine though.



Pasting the code here as well




 * @file
 * video encoding with libavcodec API example
 *
 * @example encode_video.c
 */
 #include 
 #include 
 #include 
 #include <libavcodec></libavcodec>avcodec.h>
 #include <libavutil></libavutil>opt.h>
 #include <libavutil></libavutil>imgutils.h>
 static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,
 FILE *outfile)
 {
 int ret;
 /* send the frame to the encoder */
 if (frame)
 printf("Send frame %3"PRId64"\n", frame->pts);
 ret = avcodec_send_frame(enc_ctx, frame);
 if (ret < 0) {
 fprintf(stderr, "Error sending a frame for encoding\n");
 exit(1);
 }
 while (ret >= 0) {
 ret = avcodec_receive_packet(enc_ctx, pkt);
 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
 return;
 else if (ret < 0) {
 fprintf(stderr, "Error during encoding\n");
 exit(1);
 }
 printf("Write packet %3"PRId64" (size=%5d)\n", pkt->pts, pkt->size);
 fwrite(pkt->data, 1, pkt->size, outfile);
 av_packet_unref(pkt);
 }
 }

 int main(int argc, char **argv)
 {
 const char *filename, *codec_name;
 const AVCodec *codec;
 AVCodecContext *c= NULL;
 int i, ret, x, y;
 FILE *f;
 AVFrame *frame;
 AVPacket *pkt;
 uint8_t endcode[] = { 0, 0, 1, 0xb7 };
 if (argc <= 2) {
 fprintf(stderr, "Usage: %s <output file="file"> <codec>\n", argv[0]);
 exit(0);
 }
 filename = argv[1];
 codec_name = argv[2];
 /* find the mpeg1video encoder */
 codec = avcodec_find_encoder_by_name(codec_name);
 if (!codec) {
 fprintf(stderr, "Codec '%s' not found\n", codec_name);
 exit(1);
 }
 c = avcodec_alloc_context3(codec);
 if (!c) {
 fprintf(stderr, "Could not allocate video codec context\n");
 exit(1);
 }
 pkt = av_packet_alloc();
 if (!pkt)
 exit(1);
 /* put sample parameters */
 c->bit_rate = 400000;
 /* resolution must be a multiple of two */
 c->width = 352;
 c->height = 288;
 /* frames per second */
 c->time_base = (AVRational){1, 25};
 c->framerate = (AVRational){25, 1};
 /* emit one intra frame every ten frames
 * check frame pict_type before passing frame
 * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
 * then gop_size is ignored and the output of encoder
 * will always be I frame irrespective to gop_size
 */
 c->gop_size = 10;
 c->max_b_frames = 1;
 c->pix_fmt = AV_PIX_FMT_YUV420P;
 if (codec->id == AV_CODEC_ID_H264)
 av_opt_set(c->priv_data, "preset", "slow", 0);
 /* open it */
 ret = avcodec_open2(c, codec, NULL);
 if (ret < 0) {
 fprintf(stderr, "Could not open codec: %s\n", av_err2str(ret));
 exit(1);
 }
 f = fopen(filename, "wb");
 if (!f) {
 fprintf(stderr, "Could not open %s\n", filename);
 exit(1);
 }
 frame = av_frame_alloc();
 if (!frame) {
 fprintf(stderr, "Could not allocate video frame\n");
 exit(1);
 }
 frame->format = c->pix_fmt;
 frame->width = c->width;
 frame->height = c->height;
 ret = av_frame_get_buffer(frame, 32);
 if (ret < 0) {
 fprintf(stderr, "Could not allocate the video frame data\n");
 exit(1);
 }
 /* encode 1 second of video */
 for (i = 0; i < 25; i++) {
 fflush(stdout);
 /* make sure the frame data is writable */
 ret = av_frame_make_writable(frame);
 if (ret < 0)
 exit(1);
 /* prepare a dummy image */
 /* Y */
 for (y = 0; y < c->height; y++) {
 for (x = 0; x < c->width; x++) {
 frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
 }
 }
 /* Cb and Cr */
 for (y = 0; y < c->height/2; y++) {
 for (x = 0; x < c->width/2; x++) {
 frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;
 frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
 }
 }
 frame->pts = i;
 /* encode the image */
 encode(c, frame, pkt, f);
 }
 /* flush the encoder */
 encode(c, NULL, pkt, f);
 /* add sequence end code to have a real MPEG file */
 if (codec->id == AV_CODEC_ID_MPEG1VIDEO || codec->id == AV_CODEC_ID_MPEG2VIDEO)
 fwrite(endcode, 1, sizeof(endcode), f);
 fclose(f);
 avcodec_free_context(&c);
 av_frame_free(&frame);
 av_packet_free(&pkt);
 return 0;
 }
</codec></output>


The code fails at encode call and every
avcodec_receive_packetcall returnsAVERROR(EAGAIN)


What am i missing here ?


-
Interlaced (1080i) video converted to deinterlaced (1080p) won't play in Quicktime or other players, except VLC
24 avril 2020, par cozmonautI'm trying to convert a 1080i ts video clip to 1080p mp4. I've found many different ffmpeg commands to do this, which all successfully convert to 1080p mp4, however, none of generated clips will open in Quicktime or any another other player, other than VLC. I've read about the need to have the correct color space (i.e. yuv420p) for Quicktime to work, and also that 10 bit files won't work (only 8 bit). However, when these things have been accounted for, the resulting video clips still won't open in Quicktime.






Here are the commands I've tried.



ffmpeg -i test_original_interlaced.ts -vf bwdif -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 320k test_generated_progressive.mp4

 ffmpeg -i test_original_interlaced.ts -vf yadif -c:v libx264 -preset slow -crf 19 -c:a aac -b:a 256k test_generated_progressive.mp4

 ffmpeg -i test_original_interlaced.ts -vf yadif -c:v libx264 -preset slow -crf 18 -pix_fmt yuv420p -c:a aac -b:a 256k test_generated_progressive.mp4

 ffmpeg -i test_original_interlaced.ts -vf yadif=parity=auto test_generated_progressive.mp4






Here are the 1080i ts details and link to the original video clip :



ffmpeg version 4.2.1-tessus https://evermeet.cx/ffmpeg/ Copyright (c) 2000-2019 the FFmpeg developers
 built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
 configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libmysofa --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvmaf --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-version3 --pkg-config-flags=--static --disable-ffplay
 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
 libswscale 5. 5.100 / 5. 5.100
 libswresample 3. 5.100 / 3. 5.100
 libpostproc 55. 5.100 / 55. 5.100
Input #0, mpegts, from '/Users/test_original_interlaced.ts':
 Duration: 00:00:05.26, start: 1.400000, bitrate: 15183 kb/s
 Program 1 
 Metadata:
 service_name : Service01
 service_provider: FFmpeg
 Stream #0:0[0x100]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv, top first), 1920x1080 [SAR 1:1 DAR 16:9], Closed Captions, 29.97 fps, 29.97 tbr, 90k tbn, 59.94 tbc
 Stream #0:1[0x101](eng): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz, 5.1(side), fltp, 384 kb/s



Link to original video clip (10 MB) : https://www.dropbox.com/s/85tv3v91lflfpon/test_original_interlaced.ts?dl=0






Here are the 1080p mp4 details and link to the generated video clip (that won't open in Quicktime) :



ffmpeg version 4.2.1-tessus https://evermeet.cx/ffmpeg/ Copyright (c) 2000-2019 the FFmpeg developers
 built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
 configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libmysofa --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvmaf --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-version3 --pkg-config-flags=--static --disable-ffplay
 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
 libswscale 5. 5.100 / 5. 5.100
 libswresample 3. 5.100 / 3. 5.100
 libpostproc 55. 5.100 / 55. 5.100
Guessed Channel Layout for Input Stream #0.1 : 5.1
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/test_generated_progressive.mp4':
 Metadata:
 major_brand : isom
 minor_version : 512
 compatible_brands: isomiso2avc1mp41
 encoder : Lavf58.29.100
 Duration: 00:00:05.27, start: 0.000000, bitrate: 9873 kb/s
 Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], Closed Captions, 9543 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc (default)
 Metadata:
 handler_name : VideoHandler
 Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 319 kb/s (default)
 Metadata:
 handler_name : SoundHandler



Link to generated video clip (6.5 MB) : https://www.dropbox.com/s/w744mdee5drvmya/test_generated_progressive.mp4?dl=0






Any help would be greatly appreciated.



Thank you.


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