I'm compiling a custom version of ffmpeg, and I want it to generate random file names but it does not support this, so I need some function that does this with X the quantity is not important, as long as it is above 10 and below 20), if possible, I would like to know how to do this only with numbers and with alphanumeric characters.
The purpose of this is to incorporate random file name generation by integrating this function with the existing one, hls->use_localtime / pattern_localtime_fmt which represents the generation of names based on datetime.
Using %%Y-%%m-%%dT%%H.%%M.%%S.%%I.ts with -use_localtime 1 you can get the following result 2016-10-30T15.12.32.03.ts .
Knowing this, how could I generate a random result such as 2016-10-30T15.12.32.03-41u7aai73y.ts or 016-10-30T15.12.32.03-07931993501.ts ?
Would it be possible to change the code below to implement the modifications proposed above?
The hlsenc.c code:
static int hls_write_header(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
int ret, i;
char *p;
const char *pattern = "%d.ts";
const char *pattern_localtime_fmt = "-%s.ts";
AVDictionary *options = NULL;
int basename_size;
hls->sequence = hls->start_sequence;
hls->recording_time = hls->time * AV_TIME_BASE;
hls->start_pts = AV_NOPTS_VALUE;
if (hls->format_options_str) {
ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n", hls->format_options_str);
goto fail;
}
}
for (i = 0; i < s->nb_streams; i++) {
hls->has_video +=
s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO;
}
if (hls->has_video > 1)
av_log(s, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
hls->oformat = av_guess_format("mpegts", NULL, NULL);
if (!hls->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
if (hls->segment_filename) {
hls->basename = av_strdup(hls->segment_filename);
if (!hls->basename) {
ret = AVERROR(ENOMEM);
goto fail;
}
} else {
if (hls->flags & HLS_SINGLE_FILE)
pattern = ".ts";
if (hls->use_localtime) {
basename_size = strlen(s->filename) + strlen(pattern_localtime_fmt) + 1;
} else {
basename_size = strlen(s->filename) + strlen(pattern) + 1;
}
hls->basename = av_malloc(basename_size);
if (!hls->basename) {
ret = AVERROR(ENOMEM);
goto fail;
}
av_strlcpy(hls->basename, s->filename, basename_size);
p = strrchr(hls->basename, '.');
if (p)
*p = 'static int hls_write_header(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
int ret, i;
char *p;
const char *pattern = "%d.ts";
const char *pattern_localtime_fmt = "-%s.ts";
AVDictionary *options = NULL;
int basename_size;
hls->sequence = hls->start_sequence;
hls->recording_time = hls->time * AV_TIME_BASE;
hls->start_pts = AV_NOPTS_VALUE;
if (hls->format_options_str) {
ret = av_dict_parse_string(&hls->format_options, hls->format_options_str, "=", ":", 0);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Could not parse format options list '%s'\n", hls->format_options_str);
goto fail;
}
}
for (i = 0; i < s->nb_streams; i++) {
hls->has_video +=
s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO;
}
if (hls->has_video > 1)
av_log(s, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
hls->oformat = av_guess_format("mpegts", NULL, NULL);
if (!hls->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
if (hls->segment_filename) {
hls->basename = av_strdup(hls->segment_filename);
if (!hls->basename) {
ret = AVERROR(ENOMEM);
goto fail;
}
} else {
if (hls->flags & HLS_SINGLE_FILE)
pattern = ".ts";
if (hls->use_localtime) {
basename_size = strlen(s->filename) + strlen(pattern_localtime_fmt) + 1;
} else {
basename_size = strlen(s->filename) + strlen(pattern) + 1;
}
hls->basename = av_malloc(basename_size);
if (!hls->basename) {
ret = AVERROR(ENOMEM);
goto fail;
}
av_strlcpy(hls->basename, s->filename, basename_size);
p = strrchr(hls->basename, '.');
if (p)
*p = '%pre%';
if (hls->use_localtime) {
av_strlcat(hls->basename, pattern_localtime_fmt, basename_size);
} else {
av_strlcat(hls->basename, pattern, basename_size);
}
}
if ((ret = hls_mux_init(s)) < 0)
goto fail;
if ((ret = hls_start(s)) < 0)
goto fail;
av_dict_copy(&options, hls->format_options, 0);
ret = avformat_write_header(hls->avf, &options);
if (av_dict_count(options)) {
av_log(s, AV_LOG_ERROR, "Some of provided format options in '%s' are not recognized\n", hls->format_options_str);
ret = AVERROR(EINVAL);
goto fail;
}
av_assert0(s->nb_streams == hls->avf->nb_streams);
for (i = 0; i < s->nb_streams; i++) {
AVStream *inner_st = hls->avf->streams[i];
AVStream *outer_st = s->streams[i];
avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
}
fail:
av_dict_free(&options);
if (ret < 0) {
av_freep(&hls->basename);
if (hls->avf)
avformat_free_context(hls->avf);
}
return ret;
}
';
if (hls->use_localtime) {
av_strlcat(hls->basename, pattern_localtime_fmt, basename_size);
} else {
av_strlcat(hls->basename, pattern, basename_size);
}
}
if ((ret = hls_mux_init(s)) < 0)
goto fail;
if ((ret = hls_start(s)) < 0)
goto fail;
av_dict_copy(&options, hls->format_options, 0);
ret = avformat_write_header(hls->avf, &options);
if (av_dict_count(options)) {
av_log(s, AV_LOG_ERROR, "Some of provided format options in '%s' are not recognized\n", hls->format_options_str);
ret = AVERROR(EINVAL);
goto fail;
}
av_assert0(s->nb_streams == hls->avf->nb_streams);
for (i = 0; i < s->nb_streams; i++) {
AVStream *inner_st = hls->avf->streams[i];
AVStream *outer_st = s->streams[i];
avpriv_set_pts_info(outer_st, inner_st->pts_wrap_bits, inner_st->time_base.num, inner_st->time_base.den);
}
fail:
av_dict_free(&options);
if (ret < 0) {
av_freep(&hls->basename);
if (hls->avf)
avformat_free_context(hls->avf);
}
return ret;
}
This is just a snippet of hlsenc.c .