[FFmpeg-cvslog] hlsenc: Support recovery from an already present playlist
Luca Barbato
git at videolan.org
Wed Nov 1 18:55:54 EET 2017
ffmpeg | branch: master | Luca Barbato <lu_zero at gentoo.org> | Fri May 19 20:32:47 2017 +0200| [16cb06bb30390c3d74312fc6aead818e19bfd8e4] | committer: Luca Barbato
hlsenc: Support recovery from an already present playlist
Parse the playlist to recover the start sequence and previously
generated segments and continue muxing from there.
Mainly useful for near-seamless recovery in live scenarios.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=16cb06bb30390c3d74312fc6aead818e19bfd8e4
---
libavformat/hlsenc.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 85 insertions(+), 10 deletions(-)
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index 7aef02b805..c84dd82e7d 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -119,7 +119,7 @@ static int setup_encryption(AVFormatContext *s)
AVIOContext *out = NULL;
int len, ret;
uint8_t buf[16];
- uint8_t *k;
+ uint8_t *k = NULL;
len = strlen(hls->basename) + 4 + 1;
hls->key_basename = av_mallocz(len);
@@ -141,9 +141,22 @@ static int setup_encryption(AVFormatContext *s)
return ret;
k = hls->key;
} else {
- if ((ret = randomize(buf, sizeof(buf))) < 0) {
- av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
- return ret;
+ if (hls->start_sequence < 0) {
+ ret = s->io_open(s, &out, hls->key_basename, AVIO_FLAG_READ, NULL);
+ if (ret < 0) {
+ av_log(s, AV_LOG_WARNING,
+ "Cannot recover the key, generating a new one.\n");
+ } else {
+ avio_read(out, buf, 16);
+ k = buf;
+ avio_close(out);
+ }
+ }
+ if (!k) {
+ if ((ret = randomize(buf, sizeof(buf))) < 0) {
+ av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
+ return ret;
+ }
}
if ((ret = dict_set_bin(&hls->enc_opts, "key", buf, sizeof(buf))) < 0)
@@ -201,14 +214,14 @@ static int hls_mux_init(AVFormatContext *s)
return 0;
}
-static int append_entry(HLSContext *hls, int64_t duration)
+static int append_entry(HLSContext *hls, int64_t duration, const char *name)
{
ListEntry *en = av_malloc(sizeof(*en));
if (!en)
return AVERROR(ENOMEM);
- av_strlcpy(en->name, av_basename(hls->avf->filename), sizeof(en->name));
+ av_strlcpy(en->name, name, sizeof(en->name));
en->duration = duration;
en->next = NULL;
@@ -356,12 +369,67 @@ fail:
return err;
}
+static int read_chomp_line(AVIOContext *s, char *buf, int maxlen)
+{
+ int len = ff_get_line(s, buf, maxlen);
+ while (len > 0 && av_isspace(buf[len - 1]))
+ buf[--len] = '\0';
+ return len;
+}
+
+static int hls_recover(AVFormatContext *s)
+{
+ HLSContext *hls = s->priv_data;
+ char line[1024];
+ AVIOContext *io;
+ const char *ptr;
+ int ret, is_segment = 0;
+ int64_t duration = 0;
+
+ ret = s->io_open(s, &io, s->filename, AVIO_FLAG_READ, NULL);
+ if (ret < 0) {
+ av_log(s, AV_LOG_WARNING,
+ "Cannot recover the playlist, generating a new one.\n");
+ hls->start_sequence = 0;
+ hls->sequence = 0;
+ return 0;
+ }
+
+ read_chomp_line(io, line, sizeof(line));
+ if (strcmp(line, "#EXTM3U")) {
+ av_log(s, AV_LOG_ERROR,
+ "The playlist file is present but unparsable."
+ " Please remove it.\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ while (!io->eof_reached) {
+ read_chomp_line(io, line, sizeof(line));
+ if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
+ hls->sequence = hls->start_sequence = atoi(ptr);
+ } else if (av_strstart(line, "#EXTINF:", &ptr)) {
+ is_segment = 1;
+ duration = atof(ptr) * AV_TIME_BASE;
+ } else if (av_strstart(line, "#", NULL)) {
+ continue;
+ } else if (line[0]) {
+ if (is_segment) {
+ append_entry(hls, duration, av_basename(line));
+ is_segment = 0;
+ }
+ }
+ }
+
+ return 0;
+}
+
static int hls_setup(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
const char *pattern = "%d.ts";
int basename_size = strlen(s->filename) + strlen(pattern) + 1;
char *p;
+ int ret;
if (hls->encrypt)
basename_size += 7;
@@ -382,7 +450,13 @@ static int hls_setup(AVFormatContext *s)
*p = '\0';
if (hls->encrypt) {
- int ret = setup_encryption(s);
+ ret = setup_encryption(s);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (hls->start_sequence < 0) {
+ ret = hls_recover(s);
if (ret < 0)
return ret;
}
@@ -465,7 +539,7 @@ static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
hls->duration = pts - hls->end_pts;
if (can_split && pts - hls->start_pts >= end_pts) {
- ret = append_entry(hls, hls->duration);
+ ret = append_entry(hls, hls->duration, av_basename(hls->avf->filename));
if (ret)
return ret;
@@ -500,7 +574,7 @@ static int hls_write_trailer(struct AVFormatContext *s)
ff_format_io_close(s, &oc->pb);
avformat_free_context(oc);
av_free(hls->basename);
- append_entry(hls, hls->duration);
+ append_entry(hls, hls->duration, av_basename(hls->avf->filename));
hls_window(s, 1);
free_entries(hls);
@@ -511,7 +585,8 @@ static int hls_write_trailer(struct AVFormatContext *s)
#define OFFSET(x) offsetof(HLSContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
- {"start_number", "first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, E},
+ {"start_number", "first number in the sequence", OFFSET(start_sequence),AV_OPT_TYPE_INT64, {.i64 = 0}, -1, INT64_MAX, E, "start_number"},
+ {"recover", "If there is already a m3u8 file in the path, populate the sequence from it", 0, AV_OPT_TYPE_CONST, {.i64 = -1}, 0, 0, E, "start_number"},
{"hls_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E},
{"hls_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E},
{"hls_wrap", "number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
More information about the ffmpeg-cvslog
mailing list