Recherche avancée
Autres articles (22)
-
Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
-
Ecrire une actualité
21 juin 2013, parPrésentez les changements dans votre MédiaSPIP ou les actualités de vos projets sur votre MédiaSPIP grâce à la rubrique actualités.
Dans le thème par défaut spipeo de MédiaSPIP, les actualités sont affichées en bas de la page principale sous les éditoriaux.
Vous pouvez personnaliser le formulaire de création d’une actualité.
Formulaire de création d’une actualité Dans le cas d’un document de type actualité, les champs proposés par défaut sont : Date de publication ( personnaliser la date de publication ) (...) -
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 (6353)
-
Dreamcast Serial Extractor
31 décembre 2017, par Multimedia Mike — Sega DreamcastIt has not been a very productive year for blogging. But I started the year by describing an unfinished project that I developed for the Sega Dreamcast, so I may as well end the year the same way. The previous project was a media player. That initiative actually met with some amount of success and could have developed into something interesting if I had kept at it.
By contrast, this post describes an effort that was ultimately a fool’s errand that I spent way too much time trying to make work.
Problem Statement
In my neverending quest to analyze the structure of video games while also hoarding a massive collection of them (though I’m proud to report that I did play at least a few of them this past year), I wanted to be able to extract the data from my many Dreamcast titles, both games and demo discs. I had a tool called the DC Coder’s Cable, a serial cable that enables communication between a Dreamcast and a PC. With the right software, you could dump an entire Dreamcast GD-ROM, which contained a gigabyte worth of sectors.Problem : The dumping software (named ‘dreamrip’ and written by noted game hacker BERO) operated in a very basic mode, methodically dumping sector after sector and sending it down the serial cable. This meant that it took about 28 hours to extract all the data on a single disc by running at the maximum speed of 115,200 bits/second, or about 11 kilobytes/second. I wanted to create a faster method.
The Pitch
I formed a mental model of dreamrip’s operation that looked like this :
As an improvement, I envisioned this beautiful architecture :
Architectural Assumptions
My proposed architecture was predicated on the assumption that the disc reading and serial output functions were both I/O-bound operations and that the CPU would be idle much of the time. My big idea was to use that presumably idle CPU time to compress the sectors before sending them over the wire. As long as the CPU can compress the data faster than 11 kbytes/sec, it should be a win. In order to achieve this, I broke the main program into 3 threads :- The first thread reads the sectors ; more specifically, it asks the drive firmware to please read the sectors and make the data available in system RAM
- The second thread waits for sector data to appear in memory and then compresses it
- The third thread takes the compressed data when it is ready and shuffles it out through the serial cable
Simple and elegant, right ?
For data track compression, I wanted to start with zlib in order to prove the architecture, but then also try bzip2 or lzma. As long as they could compress data faster than the serial port could write it, then it should be a win. For audio track compression, I wanted to use the Flake FLAC encoder. According to my notes, I did get both bzip2 compression and the Flake compressor working on the Dreamcast. I recall choosing Flake over the official FLAC encoder because it was much simpler and had fewer dependencies, always an important consideration for platforms such as this.
Problems
I worked for quite awhile on this project. I have a lot of notes recorded but a lot of the problems I had remain a bit vague in my memory. However, there was one problem I discovered that eventually sunk the entire initiative :The serial output operation is CPU-bound.
My initial mental model was that the a buffer could be “handed off” to the serial subsystem and the CPU could go back to doing other work. Nope. Turns out that the CPU was participating at every step of the serial transfer.
Further, I eventually dug into the serial driver code and learned that there was already some compression taking place via the miniLZO library.
Lessons Learned
- Recognize the assumptions that you’re making up front at the start of the project.
- Prototype in order to ensure plausibility
- Profile to make sure you’re optimizing the right thing (this is something I have learned again and again).
Another interesting tidbit from my notes : it doesn’t matter how many sectors you read at a time, the overall speed is roughly the same. I endeavored to read 1000 2048-byte data sectors, 1 or 10 or 100 at a time, or all 1000 at once. My results :
- 1 : 19442 ms
- 10 : 19207 ms
- 100 : 19194 ms
- 1000 : 19320 ms
No difference. That surprised me.
Side Benefits
At one point, I needed to understand how BERO’s dreamrip software was operating. I knew I used to have the source code but I could no longer find it. Instead, I decided to try to reverse engineer what I needed from the SH-4 binary image that I had. It wasn’t an ELF image ; rather, it was a raw binary meant to be loaded at a particular memory location which makes it extra challenging for ‘objdump’. This led to me asking my most viewed and upvoted question on Stack Overflow : “Disassembling A Flat Binary File Using objdump”. The next day, it also led me to post one of my most upvoted answers when I found the solution elsewhere.Strangely, I have since tried out the command line shown in my answer and have been unable to make it work. But people keep upvoting both the question and the answer.
Eventually this all became moot when I discovered a misplaced copy of the source code on one of my computers.
I strongly recall binging through the Alias TV show while I was slogging away on this project, so I guess that’s a positive association since I got so many fun screenshots out of it.
The Final Resolution
Strangely, I was still determined to make this project work even though the Dreamcast SD adapter arrived for me about halfway through the effort. Part of this was just stubbornness, but part of it was my assumptions about serial port speeds, in particular, my assumption that there was a certain speed-of-light type of limitation on serial port speeds so that the SD adapter, operating over the DC’s serial port, would not be appreciably faster than the serial cable.This turned out to be very incorrect. In fact, the SD adapter is capable of extracting an entire gigabyte disc image in 35-40 minutes. This is the method I have since been using to extract Dreamcast disc images.
The post Dreamcast Serial Extractor first appeared on Breaking Eggs And Making Omelettes.
-
FFmpeg:A General error in an external library occurred when using FFmpeg6.1's avcodec_send_frame
4 janvier 2024, par MMingYI have the same code that can successfully push streams (rtmp) in the environment, but in the Android environment, I fail with an error message. The error message method is avcodec_send_frame in ffmpeg6.1. By the way, I compiled the FFmpeg library on Android myself, and I downloaded the official package for Win11. I will provide the code for Android and Win11 below.


android :


static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,

 AVFormatContext *outFormatCtx) {
 int ret;

 /* send the frame to the encoder */
 if (frame)
 LOGE2("Send frame %ld\n", frame->pts);

 ret = avcodec_send_frame(enc_ctx, frame);
 if (ret < 0) {
 char errbuf[AV_ERROR_MAX_STRING_SIZE];
 av_strerror(ret, errbuf, AV_ERROR_MAX_STRING_SIZE);
 LOGE2("Error sending a frame for encoding ,%s\n", errbuf);
// exit(1);
 return;
 }

 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 (size=%5d)\n", pkt->pts);
 /* ret = av_interleaved_write_frame(outFormatCtx, pkt);
 if (ret < 0) {
 LOGE2("write frame err=%s", av_err2str(ret));
 break;
 }*/
// printf("Write packet %3"PRId64" (size=%5d)\n", pkt->pts, pkt->size);
 av_write_frame(outFormatCtx, pkt); // Write the packet to the RTMP stream
 av_packet_unref(pkt);
 }
}

PUSHER_FUNC(int, testPush, jstring yuvPath, jstring outputPath) {
 const char *yvu_path = env->GetStringUTFChars(yuvPath, JNI_FALSE);
 const char *output_path = env->GetStringUTFChars(outputPath, JNI_FALSE);
 const char *rtmp_url = output_path;
 const AVCodec *codec;
 AVCodecContext *codecContext = NULL;
 AVFormatContext *outFormatCtx;
 int ret = 0;
 AVStream *outStream;
 AVFrame *frame;
 AVPacket *pkt;
 int i, x, y;
 avformat_network_init();

 codec = avcodec_find_encoder(AV_CODEC_ID_H264);
// codec = avcodec_find_encoder(AV_CODEC_ID_MPEG4);
// codec = avcodec_find_encoder(AV_CODEC_ID_H265);
 if (!codec) {
 LOGE2("JNI Error finding H.264 encoder");
 return -1;
 }
 codecContext = avcodec_alloc_context3(codec);
 if (!codecContext) {
 fprintf(stderr, "Could not allocate video codec context\n");
 return -1;
 }

 /* Allocate the output context */
 outFormatCtx = avformat_alloc_context();
 if (!outFormatCtx) {
 fprintf(stderr, "Could not allocate output context\n");
 return -1;
 }

 /* Open the RTMP output */
 const AVOutputFormat *ofmt = av_guess_format("flv", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("mpegts", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("mp4", NULL, NULL);
 if (!ofmt) {
 fprintf(stderr, "Could not find output format\n");
 return -1;
 }
 outFormatCtx->oformat = ofmt;
 outFormatCtx->url = av_strdup(rtmp_url);
 /* Add a video stream */
 outStream = avformat_new_stream(outFormatCtx, codec);
 if (!outStream) {
 fprintf(stderr, "Could not allocate stream\n");
 return -1;
 }
 outStream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 outStream->codecpar->codec_id = codec->id;
 outStream->codecpar->width = 352;
 outStream->codecpar->height = 288;

 /* Set the output URL */
 av_dict_set(&outFormatCtx->metadata, "url", rtmp_url, 0);

 pkt = av_packet_alloc();
 if (!pkt)
 return -1;

 /* ... (rest of the setup code) ... */
/* put sample parameters */
 codecContext->bit_rate = 400000;
 /* resolution must be a multiple of two */
 codecContext->width = 352;
 codecContext->height = 288;
 /* frames per second */
 codecContext->time_base = (AVRational) {1, 25};
 codecContext->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
 */
 codecContext->gop_size = 10;
 codecContext->max_b_frames = 1;
 codecContext->pix_fmt = AV_PIX_FMT_YUV420P;

 if (codec->id == AV_CODEC_ID_H264)
 av_opt_set(codecContext->priv_data, "preset", "slow", 0);

 /* open it */
 ret = avcodec_open2(codecContext, codec, NULL);
 if (ret < 0) {
 LOGE2("JNI Error opening codec eer%s", av_err2str(ret));
 return ret;
 }

 avcodec_parameters_to_context(codecContext, outStream->codecpar);

 if (avio_open(&outFormatCtx->pb, rtmp_url, AVIO_FLAG_WRITE)) {
 fprintf(stderr, "Could not open output\n");
 return ret;
 }
 /* Write the header */
 if (avformat_write_header(outFormatCtx, NULL) != 0) {
 fprintf(stderr, "Error occurred when opening output\n");
 return ret;
 }

 frame = av_frame_alloc();
 if (!frame) {
 fprintf(stderr, "Could not allocate video frame\n");
 return -1;
 }
 frame->format = codecContext->pix_fmt;
 frame->format = AV_PIX_FMT_YUV420P;
 frame->format = 0;
 frame->width = codecContext->width;
 frame->height = codecContext->height;

 ret = av_frame_get_buffer(frame, 0);
 if (ret < 0) {
 fprintf(stderr, "Could not allocate the video frame data ,%s\n", av_err2str(ret));
 return ret;
 }

 /* FILE *yuv_file = fopen(yvu_path, "rb");
 if (yuv_file == NULL) {
 LOGE2("cannot open h264 file");
 return -1;
 }*/

 /* encode 1 second of video */
 for (i = 0; i < 25000; i++) {
// 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 < codecContext->height; y++) {
 for (x = 0; x < codecContext->width; x++) {
 frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
 }
 }

 /* Cb and Cr */
 for (y = 0; y < codecContext->height / 2; y++) {
 for (x = 0; x < codecContext->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(codecContext, frame, pkt, outFormatCtx);
 }

// fclose(yuv_file);

 /* flush the encoder */
 encode(codecContext, NULL, pkt, outFormatCtx);

 /* Write the trailer */
 av_write_trailer(outFormatCtx);

 /* Close the output */
 avformat_free_context(outFormatCtx);

 avcodec_free_context(&codecContext);
 av_frame_free(&frame);
 av_packet_free(&pkt);
}


win11：


#include 
#include 
#include 

#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>opt.h>
#include <libavutil></libavutil>imgutils.h>
#include <libavutil></libavutil>time.h>

static void encode(AVCodecContext *enc_ctx, AVFrame *frame, AVPacket *pkt,
 AVFormatContext *outFormatCtx) {
 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) {
 char errbuf[AV_ERROR_MAX_STRING_SIZE];
 av_strerror(ret, errbuf, AV_ERROR_MAX_STRING_SIZE);
 fprintf(stderr, "Error sending a frame for encoding ,%s\n", errbuf);
 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);
 av_write_frame(outFormatCtx, pkt); // Write the packet to the RTMP stream
 av_packet_unref(pkt);
 }
}

int main(int argc, char **argv) {
 av_log_set_level(AV_LOG_DEBUG);
 const char *rtmp_url, *codec_name;
 const AVCodec *codec;
 AVCodecContext *codecContext = NULL;
 int i, ret, x, y;
 AVFormatContext *outFormatCtx;
 AVStream *st;
 AVFrame *frame;
 AVPacket *pkt;
 uint8_t endcode[] = {0, 0, 1, 0xb7};

 if (argc <= 3) {
 fprintf(stderr, "Usage: %s <rtmp url="url"> <codec>\n", argv[0]);
 exit(0);
 }
 rtmp_url = argv[1];
 codec_name = argv[2];
 avformat_network_init();
 /* find the mpeg1video encoder */
// codec = avcodec_find_encoder_by_name(codec_name);
// codec = avcodec_find_encoder(AV_CODEC_ID_MPEG4);
// codec = avcodec_find_encoder(AV_CODEC_ID_VP9);
// codec = avcodec_find_encoder(AV_CODEC_ID_MPEG2VIDEO);
// codec = avcodec_find_encoder(AV_CODEC_ID_H264);
 codec = avcodec_find_encoder(AV_CODEC_ID_H264);
// codec = avcodec_find_encoder(AV_CODEC_ID_AV1);
// codec = avcodec_find_encoder(AV_CODEC_ID_H265);
 if (!codec) {
 fprintf(stderr, "Codec '%s' not found\n", codec_name);
 exit(1);
 }
 codecContext = avcodec_alloc_context3(codec);
 if (!codecContext) {
 fprintf(stderr, "Could not allocate video codec context\n");
 exit(1);
 }

 /* Allocate the output context */
 outFormatCtx = avformat_alloc_context();
 if (!outFormatCtx) {
 fprintf(stderr, "Could not allocate output context\n");
 exit(1);
 }

 /* Open the RTMP output */
 const AVOutputFormat *ofmt = av_guess_format("flv", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("MKV", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("rtmp", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("mpegts", NULL, NULL);
// const AVOutputFormat *ofmt = av_guess_format("mp4", NULL, NULL);
 if (!ofmt) {
 fprintf(stderr, "Could not find output format\n");
 exit(1);
 }
 outFormatCtx->oformat = ofmt;
 outFormatCtx->url = av_strdup(rtmp_url);
 /* Add a video stream */
 st = avformat_new_stream(outFormatCtx, codec);
 if (!st) {
 fprintf(stderr, "Could not allocate stream\n");
 exit(1);
 }
 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 st->codecpar->codec_id = codec->id;
 st->codecpar->width = 352;
 st->codecpar->height = 288;
// st->codecpar = c;
// st->codecpar->format = AV_PIX_FMT_YUV420P;
 // Set video stream parameters
// st->codecpar->framerate = (AVRational){25, 1};

 /* Set the output URL */
 av_dict_set(&outFormatCtx->metadata, "url", rtmp_url, 0);


 pkt = av_packet_alloc();
 if (!pkt)
 exit(1);

 /* ... (rest of the setup code) ... */
/* put sample parameters */
 codecContext->bit_rate = 400000;
 /* resolution must be a multiple of two */
 codecContext->width = 352;
 codecContext->height = 288;
 /* frames per second */
 codecContext->time_base = (AVRational) {1, 25};
 codecContext->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
 */
 codecContext->gop_size = 10;
 codecContext->max_b_frames = 1;
 codecContext->pix_fmt = AV_PIX_FMT_YUV420P;

 if (codec->id == AV_CODEC_ID_H264)
 av_opt_set(codecContext->priv_data, "preset", "slow", 0);

 /* open it */
 ret = avcodec_open2(codecContext, codec, NULL);
 if (ret < 0) {
 fprintf(stderr, "Could not open codec: %s\n", av_err2str(ret));
 exit(1);
 }

 avcodec_parameters_to_context(codecContext, st->codecpar);

 if (avio_open(&outFormatCtx->pb, rtmp_url, AVIO_FLAG_WRITE)) {
 fprintf(stderr, "Could not open output\n");
 exit(1);
 }
 /* Write the header */
 if (avformat_write_header(outFormatCtx, NULL) != 0) {
 fprintf(stderr, "Error occurred when opening output\n");
 exit(1);
 }

 frame = av_frame_alloc();
 if (!frame) {
 fprintf(stderr, "Could not allocate video frame\n");
 exit(1);
 }
// frame->format = c->pix_fmt;
// frame->format = AV_PIX_FMT_YUV420P;
 frame->format = 0;
 frame->width = codecContext->width;
 frame->height = codecContext->height;

 ret = av_frame_get_buffer(frame, 0);
 if (ret < 0) {
 fprintf(stderr, "Could not allocate the video frame data ,%s\n", av_err2str(ret));
 exit(1);
 }

 /* encode 1 second of video */
 for (i = 0; i < 2500; i++) {
 /* ... (rest of the encoding loop) ... */
 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 < codecContext->height; y++) {
 for (x = 0; x < codecContext->width; x++) {
 frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
 }
 }

 /* Cb and Cr */
 for (y = 0; y < codecContext->height / 2; y++) {
 for (x = 0; x < codecContext->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(codecContext, frame, pkt, outFormatCtx);
 }

 /* flush the encoder */
 encode(codecContext, NULL, pkt, outFormatCtx);

 /* Write the trailer */
 av_write_trailer(outFormatCtx);

 /* Close the output */
 avformat_free_context(outFormatCtx);

 avcodec_free_context(&codecContext);
 av_frame_free(&frame);
 av_packet_free(&pkt);

 return 0;
}
</codec></rtmp>

I suspect it's an issue with the ffmpeg library I compiled, so I searched for a step to compile ffmpeg on GitHub, but the package it compiled still has the same problem. I don't know what to do now.


-
FFmpeg encoding produces slightly incompatible MKV/MP4 container
11 juin 2018, par james2048I’ve been using the FFmpeg libraries to read and write media files using the C API.
So far, reading seems to be pretty straightforward. I am able to read frames which I can then process, convert to RGB, process, and then convert back to YUV420 to be encoded.
The encoded files play back with VLC media player fine, and Windows Media Player if I have a codec pack installed. However, they do behave strangely : the stock Windows 10 player won’t play them, same for Adobe Premiere. Also thumbnailers don’t work on it.
Basically it seems like nothing other than VLC or FFmpeg itself can play/process the file. I have seen this with both MP4 and MKV, so it is not a format-specific issue.The problems go away once you remux the file with FFmpeg, for example "ffmpeg -i input.mkv -c copy output.mkv". Everything can play the file correctly.
Also, the "remuxing.c" sample from the official samples works as well, with the same library version and compilers that I’m using (Visual Studio 2017, FFmpeg compiled with MinGW). It will fix the file and make it playable in all software.I’m not sure what could be causing this. I also don’t understand what the remuxing "fixed". It must be a container issue as the frames aren’t touched by remuxing.
I have analysed the output MKVs with FFprobe -show_packets. It seems to have budged the packet timestamps a little constant factor, and the output stream now has
is_avc=true and nal_length_size=4 instead of is_avc=false and nal_length_size=0, but apart from that the files are identical.Now here’s the output of FFprobe with the 3 last test packets, stream info and format info for both streams. As you can see, they are identical except for a couple of field. But something in here must have been "fixed" during remuxing to make it work.
[PACKET]
codec_type=video
stream_index=0
pts=59050
pts_time=59.050000
dts=58890
dts_time=58.890000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=427
pos=277358
flags=__
[/PACKET]
[PACKET]
codec_type=video
stream_index=0
pts=58970
pts_time=58.970000
dts=58970
dts_time=58.970000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=205
pos=277792
flags=__
[/PACKET]
[PACKET]
codec_type=video
stream_index=0
pts=59130
pts_time=59.130000
dts=59050
dts_time=59.050000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=268
pos=278004
flags=__
[/PACKET]
[STREAM]
index=0
codec_name=h264
codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
profile=Main
codec_type=video
codec_time_base=1/2000
codec_tag_string=[0][0][0][0]
codec_tag=0x0000
width=720
height=576
coded_width=720
coded_height=576
has_b_frames=2
sample_aspect_ratio=N/A
display_aspect_ratio=N/A
pix_fmt=yuv420p
level=50
color_range=unknown
color_space=unknown
color_transfer=unknown
color_primaries=unknown
chroma_location=left
field_order=progressive
timecode=N/A
refs=1
is_avc=false
nal_length_size=0
id=N/A
r_frame_rate=299/12
avg_frame_rate=1000/1
time_base=1/1000
start_pts=0
start_time=0.000000
duration_ts=N/A
duration=N/A
bit_rate=N/A
max_bit_rate=N/A
bits_per_raw_sample=8
nb_frames=N/A
nb_read_frames=N/A
nb_read_packets=737
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
DISPOSITION:timed_thumbnails=0
TAG:DURATION=00:00:59.211000000
[/STREAM]
[FORMAT]
filename=testEncLeft.mkv
nb_streams=1
nb_programs=0
format_name=matroska,webm
format_long_name=Matroska / WebM
start_time=0.000000
duration=59.211000
size=278349
bit_rate=37607
probe_score=100
TAG:COMMENT=Slickline Player Export
TAG:ENCODER=Lavf57.83.100
[/FORMAT]And the info after remuxing, which works :
[PACKET]
codec_type=video
stream_index=0
pts=59050
pts_time=59.050000
dts=58890
dts_time=58.890000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=427
pos=277418
flags=__
[/PACKET]
[PACKET]
codec_type=video
stream_index=0
pts=58970
pts_time=58.970000
dts=58970
dts_time=58.970000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=205
pos=277852
flags=__
[/PACKET]
[PACKET]
codec_type=video
stream_index=0
pts=59130
pts_time=59.130000
dts=59050
dts_time=59.050000
duration=1
duration_time=0.001000
convergence_duration=N/A
convergence_duration_time=N/A
size=268
pos=278064
flags=__
[/PACKET]
[STREAM]
index=0
codec_name=h264
codec_long_name=H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
profile=Main
codec_type=video
codec_time_base=1/2000
codec_tag_string=[0][0][0][0]
codec_tag=0x0000
width=720
height=576
coded_width=720
coded_height=576
has_b_frames=2
sample_aspect_ratio=N/A
display_aspect_ratio=N/A
pix_fmt=yuv420p
level=50
color_range=unknown
color_space=unknown
color_transfer=unknown
color_primaries=unknown
chroma_location=left
field_order=progressive
timecode=N/A
refs=1
is_avc=true
nal_length_size=4
id=N/A
r_frame_rate=299/12
avg_frame_rate=1000/1
time_base=1/1000
start_pts=0
start_time=0.000000
duration_ts=N/A
duration=N/A
bit_rate=N/A
max_bit_rate=N/A
bits_per_raw_sample=8
nb_frames=N/A
nb_read_frames=N/A
nb_read_packets=737
DISPOSITION:default=1
DISPOSITION:dub=0
DISPOSITION:original=0
DISPOSITION:comment=0
DISPOSITION:lyrics=0
DISPOSITION:karaoke=0
DISPOSITION:forced=0
DISPOSITION:hearing_impaired=0
DISPOSITION:visual_impaired=0
DISPOSITION:clean_effects=0
DISPOSITION:attached_pic=0
DISPOSITION:timed_thumbnails=0
TAG:DURATION=00:00:59.212000000
[/STREAM]
[FORMAT]
filename=fixedLeft.mkv
nb_streams=1
nb_programs=0
format_name=matroska,webm
format_long_name=Matroska / WebM
start_time=0.000000
duration=59.212000
size=278409
bit_rate=37615
probe_score=100
TAG:COMMENT=Slickline Player Export
TAG:ENCODER=Lavf58.12.100
[/FORMAT]Here is how I’m setting up the output context, for reference : it’s pretty standard, following the sample code.
int ret;
avformat_alloc_output_context2(&outputFormatCtx, nullptr, nullptr, outFilePath.c_str());
av_dict_set(&outputFormatCtx->metadata, "comment", "FFmpeg Export", 0);
if (!outputFormatCtx)
{
LOG_AND_THROW("Could not allocate output context");
}
outputVideoStream = avformat_new_stream(outputFormatCtx, nullptr);
outputVideoStream->time_base = AVRational{ 1, AV_TIME_BASE }; // Stream timebase will be used by codec
if (!outputVideoStream)
{
LOG_AND_THROW("Failed allocating output stream");
}
// defaults to "libx264"
AVCodec *outCodec = avcodec_find_encoder_by_name(selectedCodecName.c_str());
if (!outCodec)
{
LOG_AND_THROW("Failed finding output codec");
}
AVDictionary *opts = nullptr;
if (selectedCodecName == "libx264")
{
opts = getX264CodecOptions();
}
encoderCtx = avcodec_alloc_context3(outCodec);
if (!encoderCtx)
{
LOG_AND_THROW("Failed to allocate the encoder context");
}
encoderCtx->width = width;
encoderCtx->height = height;
encoderCtx->pix_fmt = AV_PIX_FMT_YUV420P;
// time base for the frames we will provide to the encoder
encoderCtx->time_base = AVRational{ 1, AV_TIME_BASE };
// convert framerate from double to rational
encoderCtx->framerate = AVRational{ (int)(frameRate * AV_TIME_BASE), AV_TIME_BASE};
// Match encoderCtx time base for the stream
outputVideoStream->time_base = encoderCtx->time_base;
ret = avcodec_open2(encoderCtx, outCodec, &opts);
if (ret < 0)
{
LOG_AND_THROW_PARAM("Cannot open video encoder for stream: %d", ret);
}
// Fill in some params for MP4 stream, details about encoder
ret = avcodec_parameters_from_context(outputVideoStream->codecpar, encoderCtx);
if (ret < 0)
{
LOG_AND_THROW_PARAM("Failed to copy encoder parameters to output stream: %d", ret);
}
if (outputFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
{
encoderCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
}
av_dump_format(outputFormatCtx, 0, filePath.c_str(), 1);
// End of encoder settings, setting up MP4
if (!(outputFormatCtx->oformat->flags & AVFMT_NOFILE))
{
ret = avio_open(&outputFormatCtx->pb, outFilePath.c_str(), AVIO_FLAG_WRITE);
if (ret < 0)
{
LOG_AND_THROW_PARAMSTR("Could not open output file '%s'", outFilePath.c_str());
}
}
ret = avformat_write_header(outputFormatCtx, nullptr);
if (ret < 0)
{
LOG_AND_THROW_PARAM("Error occurred when opening output file for writing: %d", ret);
}Can anyone help me figure out why the container is not playing properly ?
Thanks in advance.
-James
Syndiquer tout le site
