[Libav-user] "Segmentation fault" When encoding H264 video frame
M N
assemblerx86 at yandex.com
Mon Sep 12 15:59:27 EEST 2016
Hi,
My program crashes with "Segmentation Fault" error when it is in the avcodec_encode_video2() function, however, it is able to encode the audio (Or other non-H264 codecs) normally (If I choose to only encode frames in audio stream). Here is my code (Pastebin with highlighting: http://pastebin.com/V8j9J4vq):
****************************************
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libavutil/avutil.h>
#include <libavutil/rational.h>
#include <stdio.h>
int main()
{
av_register_all();
//av_log_set_level(-8);
AVFormatContext *ps = avformat_alloc_context();
AVFormatContext *ps2 = NULL;//avformat_alloc_context();
AVOutputFormat *oF = av_guess_format("mp4", NULL, "video/mp4");
if(avformat_open_input(&ps, "vid.mp4", NULL, NULL) != 0)
{
printf("Failed to open input file.\n");
return -1;
}
avformat_alloc_output_context2(&ps2, oF, NULL, "vid2.mp4");
avformat_find_stream_info(ps, NULL);
AVCodecContext **pC = (AVCodecContext**)malloc(ps->nb_streams), **p2C = (AVCodecContext**)malloc(ps->nb_streams);
AVStream *oStream = NULL;
AVStream *iStream = NULL;
AVCodec *encoder = NULL;
AVCodec *decoder = NULL;
unsigned int i;
avio_open(&ps2->pb, "vid2.mp4", AVIO_FLAG_WRITE);
for(i = 0; i < ps->nb_streams; i++)
{
printf("%d\n", i);
iStream = ps->streams[i];
pC[i] = iStream->codec;
if(pC[i]->codec_type == AVMEDIA_TYPE_UNKNOWN) {
printf("Skipping bad stream\n");
continue;
}
oStream = avformat_new_stream(ps2, NULL);
//avcodec_parameters_copy(oStream->codecpar, iStream->codecpar);
p2C[i] = oStream->codec;
if(pC[i]->codec_type == AVMEDIA_TYPE_VIDEO || pC[i]->codec_type == AVMEDIA_TYPE_AUDIO)
{
encoder = avcodec_find_encoder(pC[i]->codec_id);
if (!encoder) {
av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
return AVERROR_INVALIDDATA;
}
//AVCodecParameters *pars = avcodec_parameters_alloc();
//avcodec_parameters_from_context(pars, pC[i]);
//avcodec_parameters_to_context(p2C[i], pars);
if(pC[i]->codec_type == AVMEDIA_TYPE_VIDEO) {
p2C[i]->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
p2C[i]->height = pC[i]->height;
p2C[i]->width = pC[i]->width;
p2C[i]->sample_aspect_ratio = pC[i]->sample_aspect_ratio;
p2C[i]->gop_size = pC[i]->gop_size;
//take first format from list of supported formats
if (encoder->pix_fmts)
p2C[i]->pix_fmt = encoder->pix_fmts[0];
else
p2C[i]->pix_fmt = pC[i]->pix_fmt;
//video time_base can be set to whatever is handy and supported by encoder
oStream->time_base = iStream->time_base;
p2C[i]->time_base = pC[i]->time_base;
} else {
p2C[i]->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
p2C[i]->sample_rate = pC[i]->sample_rate;
p2C[i]->channel_layout = pC[i]->channel_layout;
p2C[i]->channels = av_get_channel_layout_nb_channels(p2C[i]->channel_layout);
// take first format from list of supported formats
p2C[i]->sample_fmt = encoder->sample_fmts[0];
oStream->time_base = (AVRational){1, p2C[i]->sample_rate};
p2C[i]->time_base = (AVRational){1, p2C[i]->sample_rate};
}
//AVCodecParameters *par = avcodec_parameters_alloc();
//avcodec_parameters_from_context(par, pC[i]);
//avcodec_parameters_to_context(p2C[i], par);
decoder = avcodec_find_decoder(pC[i]->codec_id);
if(decoder == NULL) printf("Couldn't find decoder\n");
avcodec_open2(pC[i], decoder, NULL);
avcodec_open2(p2C[i], encoder, NULL);
//p2C-> = pC[i]->pts;
}
else if (pC[i]->codec_type == AVMEDIA_TYPE_UNKNOWN) {
av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
//return AVERROR_INVALIDDATA;
}
else
{
avcodec_copy_context(oStream->codec, iStream->codec);
printf("BUG\n");
}
}
printf("done\n");
int ret = avformat_write_header(ps2, NULL);
char err[200];
av_make_error_string(err, 200, ret);
printf("Write header %d: %s\n", ret, err);
unsigned int j = 0;
for(;; ++j)
{
AVPacket pkts;// = av_packet_alloc();
AVPacket pktr;// = av_packet_alloc();
AVFrame *rawFrame = av_frame_alloc();
av_init_packet(&pkts);
av_init_packet(&pktr);
if(av_read_frame(ps, &pkts) != 0) break;
int stream_index = pkts.stream_index;
pkts.dts = av_rescale_q_rnd(pkts.dts, ps2->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
pkts.pts = av_rescale_q_rnd(pkts.pts, ps->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
pkts.duration = av_rescale_q(pkts.duration, ps2->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base);
pktr.dts = av_rescale_q_rnd(pktr.dts, ps2->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
pktr.pts = av_rescale_q_rnd(pktr.pts, ps->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
pktr.duration = av_rescale_q(pktr.duration, ps2->streams[stream_index]->codec->time_base, ps2->streams[stream_index]->time_base);
int got_out;
if(pkts.stream_index == 0)
{
if(avcodec_decode_video2(pC[pkts.stream_index], rawFrame, &got_out, &pkts) >= 0)
{
if(avcodec_encode_video2(p2C[pkts.stream_index], &pktr, rawFrame, &got_out) == 0)
{
if(av_interleaved_write_frame(ps2, &pktr) == 0)
{
printf("SUCCESSFULLY WROTE PACKET\n");
//break;
}
} else printf("Failed to encode video\n");
} else printf("Failed to decode video\n");
}
else
{
if(avcodec_decode_audio4(pC[pkts.stream_index], rawFrame, &got_out, &pkts) >= 0)
{
if(avcodec_encode_audio2(p2C[pkts.stream_index], &pktr, rawFrame, &got_out) == 0)
{
if(av_interleaved_write_frame(ps2, &pktr) == 0)
{
printf("SUCCESSFULLY WROTE PACKET\n");
//break;
}
} else printf("Failed to encode audio\n");
} else printf("Failed to decode audio\n");
}
av_frame_free(&rawFrame);
}
if(av_write_trailer(ps2) == 0) printf("Wrote trailer\n");
}
****************************************
Thanks in advance.
More information about the Libav-user
mailing list