[FFmpeg-cvslog] avformat/hls: add support for EXT-X-MAP
Anssi Hannula
git at videolan.org
Thu Oct 15 14:10:15 CEST 2015
ffmpeg | branch: master | Anssi Hannula <anssi.hannula at iki.fi> | Thu Oct 15 14:23:00 2015 +0300| [909907948846dedf57a730a4d115d04d1117f9e5] | committer: Anssi Hannula
avformat/hls: add support for EXT-X-MAP
Without EXT-X-MAP support we miss the first bytes of some streams.
These streams worked by luck before byte-ranged segment support was added in
da7759b3579de3e98deb1ac58e642b861280ba54
Fixes ticket #4797.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=909907948846dedf57a730a4d115d04d1117f9e5
---
libavformat/hls.c | 192 ++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 182 insertions(+), 10 deletions(-)
diff --git a/libavformat/hls.c b/libavformat/hls.c
index 3c073e0..d3efd5c 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -73,6 +73,8 @@ struct segment {
char *key;
enum KeyType key_type;
uint8_t iv[16];
+ /* associated Media Initialization Section, treated as a segment */
+ struct segment *init_section;
};
struct rendition;
@@ -110,6 +112,13 @@ struct playlist {
int64_t cur_seg_offset;
int64_t last_load_time;
+ /* Currently active Media Initialization Section */
+ struct segment *cur_init_section;
+ uint8_t *init_sec_buf;
+ unsigned int init_sec_buf_size;
+ unsigned int init_sec_data_len;
+ unsigned int init_sec_buf_read_offset;
+
char key_url[MAX_URL_SIZE];
uint8_t key[16];
@@ -135,6 +144,11 @@ struct playlist {
* multiple (playlist-less) renditions associated with them. */
int n_renditions;
struct rendition **renditions;
+
+ /* Media Initialization Sections (EXT-X-MAP) associated with this
+ * playlist, if any. */
+ int n_init_sections;
+ struct segment **init_sections;
};
/*
@@ -206,16 +220,29 @@ static void free_segment_list(struct playlist *pls)
pls->n_segments = 0;
}
+static void free_init_section_list(struct playlist *pls)
+{
+ int i;
+ for (i = 0; i < pls->n_init_sections; i++) {
+ av_freep(&pls->init_sections[i]->url);
+ av_freep(&pls->init_sections[i]);
+ }
+ av_freep(&pls->init_sections);
+ pls->n_init_sections = 0;
+}
+
static void free_playlist_list(HLSContext *c)
{
int i;
for (i = 0; i < c->n_playlists; i++) {
struct playlist *pls = c->playlists[i];
free_segment_list(pls);
+ free_init_section_list(pls);
av_freep(&pls->renditions);
av_freep(&pls->id3_buf);
av_dict_free(&pls->id3_initial);
ff_id3v2_free_extra_meta(&pls->id3_deferred_extra);
+ av_freep(&pls->init_sec_buf);
av_free_packet(&pls->pkt);
av_freep(&pls->pb.buffer);
if (pls->input)
@@ -353,6 +380,60 @@ static void handle_key_args(struct key_info *info, const char *key,
}
}
+struct init_section_info {
+ char uri[MAX_URL_SIZE];
+ char byterange[32];
+};
+
+static struct segment *new_init_section(struct playlist *pls,
+ struct init_section_info *info,
+ const char *url_base)
+{
+ struct segment *sec;
+ char *ptr;
+ char tmp_str[MAX_URL_SIZE];
+
+ if (!info->uri[0])
+ return NULL;
+
+ sec = av_mallocz(sizeof(*sec));
+ if (!sec)
+ return NULL;
+
+ ff_make_absolute_url(tmp_str, sizeof(tmp_str), url_base, info->uri);
+ sec->url = av_strdup(tmp_str);
+ if (!sec->url) {
+ av_free(sec);
+ return NULL;
+ }
+
+ if (info->byterange[0]) {
+ sec->size = atoi(info->byterange);
+ ptr = strchr(info->byterange, '@');
+ if (ptr)
+ sec->url_offset = atoi(ptr+1);
+ } else {
+ /* the entire file is the init section */
+ sec->size = -1;
+ }
+
+ dynarray_add(&pls->init_sections, &pls->n_init_sections, sec);
+
+ return sec;
+}
+
+static void handle_init_section_args(struct init_section_info *info, const char *key,
+ int key_len, char **dest, int *dest_len)
+{
+ if (!strncmp(key, "URI=", key_len)) {
+ *dest = info->uri;
+ *dest_len = sizeof(info->uri);
+ } else if (!strncmp(key, "BYTERANGE=", key_len)) {
+ *dest = info->byterange;
+ *dest_len = sizeof(info->byterange);
+ }
+}
+
struct rendition_info {
char type[16];
char uri[MAX_URL_SIZE];
@@ -560,6 +641,7 @@ static int parse_playlist(HLSContext *c, const char *url,
uint8_t *new_url = NULL;
struct variant_info variant_info;
char tmp_str[MAX_URL_SIZE];
+ struct segment *cur_init_section = NULL;
if (!in) {
#if 1
@@ -645,6 +727,14 @@ static int parse_playlist(HLSContext *c, const char *url,
pls->type = PLS_TYPE_EVENT;
else if (!strcmp(ptr, "VOD"))
pls->type = PLS_TYPE_VOD;
+ } else if (av_strstart(line, "#EXT-X-MAP:", &ptr)) {
+ struct init_section_info info = {{0}};
+ ret = ensure_playlist(c, &pls, url);
+ if (ret < 0)
+ goto fail;
+ ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_init_section_args,
+ &info);
+ cur_init_section = new_init_section(pls, &info, url);
} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
if (pls)
pls->finished = 1;
@@ -723,6 +813,8 @@ static int parse_playlist(HLSContext *c, const char *url,
seg->url_offset = 0;
seg_offset = 0;
}
+
+ seg->init_section = cur_init_section;
}
}
}
@@ -736,17 +828,22 @@ fail:
return ret;
}
+static struct segment *current_segment(struct playlist *pls)
+{
+ return pls->segments[pls->cur_seq_no - pls->start_seq_no];
+}
+
enum ReadFromURLMode {
READ_NORMAL,
READ_COMPLETE,
};
/* read from URLContext, limiting read to current segment */
-static int read_from_url(struct playlist *pls, uint8_t *buf, int buf_size,
+static int read_from_url(struct playlist *pls, struct segment *seg,
+ uint8_t *buf, int buf_size,
enum ReadFromURLMode mode)
{
int ret;
- struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
/* limit read if the segment was only a part of a file */
if (seg->size >= 0)
@@ -869,12 +966,13 @@ static void intercept_id3(struct playlist *pls, uint8_t *buf,
int bytes;
int id3_buf_pos = 0;
int fill_buf = 0;
+ struct segment *seg = current_segment(pls);
/* gather all the id3 tags */
while (1) {
/* see if we can retrieve enough data for ID3 header */
if (*len < ID3v2_HEADER_SIZE && buf_size >= ID3v2_HEADER_SIZE) {
- bytes = read_from_url(pls, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);
+ bytes = read_from_url(pls, seg, buf + *len, ID3v2_HEADER_SIZE - *len, READ_COMPLETE);
if (bytes > 0) {
if (bytes == ID3v2_HEADER_SIZE - *len)
@@ -895,7 +993,6 @@ static void intercept_id3(struct playlist *pls, uint8_t *buf,
break;
if (ff_id3v2_match(buf, ID3v2_DEFAULT_MAGIC)) {
- struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
int64_t maxsize = seg->size >= 0 ? seg->size : 1024*1024;
int taglen = ff_id3v2_tag_len(buf);
int tag_got_bytes = FFMIN(taglen, *len);
@@ -927,7 +1024,7 @@ static void intercept_id3(struct playlist *pls, uint8_t *buf,
if (remaining > 0) {
/* read the rest of the tag in */
- if (read_from_url(pls, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)
+ if (read_from_url(pls, seg, pls->id3_buf + id3_buf_pos, remaining, READ_COMPLETE) != remaining)
break;
id3_buf_pos += remaining;
av_log(pls->ctx, AV_LOG_DEBUG, "Stripped additional %d HLS ID3 bytes\n", remaining);
@@ -941,7 +1038,7 @@ static void intercept_id3(struct playlist *pls, uint8_t *buf,
/* re-fill buffer for the caller unless EOF */
if (*len >= 0 && (fill_buf || *len == 0)) {
- bytes = read_from_url(pls, buf + *len, buf_size - *len, READ_NORMAL);
+ bytes = read_from_url(pls, seg, buf + *len, buf_size - *len, READ_NORMAL);
/* ignore error if we already had some data */
if (bytes >= 0)
@@ -961,11 +1058,10 @@ static void intercept_id3(struct playlist *pls, uint8_t *buf,
pls->is_id3_timestamped = (pls->id3_mpegts_timestamp != AV_NOPTS_VALUE);
}
-static int open_input(HLSContext *c, struct playlist *pls)
+static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg)
{
AVDictionary *opts = NULL;
int ret;
- struct segment *seg = pls->segments[pls->cur_seq_no - pls->start_seq_no];
// broker prior HTTP options that should be consistent across requests
av_dict_set(&opts, "user-agent", c->user_agent, 0);
@@ -1048,6 +1144,66 @@ cleanup:
return ret;
}
+static int update_init_section(struct playlist *pls, struct segment *seg)
+{
+ static const int max_init_section_size = 1024*1024;
+ HLSContext *c = pls->parent->priv_data;
+ int64_t sec_size;
+ int64_t urlsize;
+ int ret;
+
+ if (seg->init_section == pls->cur_init_section)
+ return 0;
+
+ pls->cur_init_section = NULL;
+
+ if (!seg->init_section)
+ return 0;
+
+ /* this will clobber playlist URLContext stuff, so this should be
+ * called between segments only */
+ ret = open_input(c, pls, seg->init_section);
+ if (ret < 0) {
+ av_log(pls->parent, AV_LOG_WARNING,
+ "Failed to open an initialization section in playlist %d\n",
+ pls->index);
+ return ret;
+ }
+
+ if (seg->init_section->size >= 0)
+ sec_size = seg->init_section->size;
+ else if ((urlsize = ffurl_size(pls->input)) >= 0)
+ sec_size = urlsize;
+ else
+ sec_size = max_init_section_size;
+
+ av_log(pls->parent, AV_LOG_DEBUG,
+ "Downloading an initialization section of size %"PRId64"\n",
+ sec_size);
+
+ sec_size = FFMIN(sec_size, max_init_section_size);
+
+ av_fast_malloc(&pls->init_sec_buf, &pls->init_sec_buf_size, sec_size);
+
+ ret = read_from_url(pls, seg->init_section, pls->init_sec_buf,
+ pls->init_sec_buf_size, READ_COMPLETE);
+ ffurl_close(pls->input);
+ pls->input = NULL;
+
+ if (ret < 0)
+ return ret;
+
+ pls->cur_init_section = seg->init_section;
+ pls->init_sec_data_len = ret;
+ pls->init_sec_buf_read_offset = 0;
+
+ /* spec says audio elementary streams do not have media initialization
+ * sections, so there should be no ID3 timestamps */
+ pls->is_id3_timestamped = 0;
+
+ return 0;
+}
+
static int64_t default_reload_interval(struct playlist *pls)
{
return pls->n_segments > 0 ?
@@ -1068,6 +1224,7 @@ restart:
if (!v->input) {
int64_t reload_interval;
+ struct segment *seg;
/* Check that the playlist is still needed before opening a new
* segment. */
@@ -1121,7 +1278,14 @@ reload:
goto reload;
}
- ret = open_input(c, v);
+ seg = current_segment(v);
+
+ /* load/update Media Initialization Section, if any */
+ ret = update_init_section(v, seg);
+ if (ret)
+ return ret;
+
+ ret = open_input(c, v, seg);
if (ret < 0) {
if (ff_check_interrupt(c->interrupt_callback))
return AVERROR_EXIT;
@@ -1133,7 +1297,15 @@ reload:
just_opened = 1;
}
- ret = read_from_url(v, buf, buf_size, READ_NORMAL);
+ if (v->init_sec_buf_read_offset < v->init_sec_data_len) {
+ /* Push init section out first before first actual segment */
+ int copy_size = FFMIN(v->init_sec_data_len - v->init_sec_buf_read_offset, buf_size);
+ memcpy(buf, v->init_sec_buf, copy_size);
+ v->init_sec_buf_read_offset += copy_size;
+ return copy_size;
+ }
+
+ ret = read_from_url(v, current_segment(v), buf, buf_size, READ_NORMAL);
if (ret > 0) {
if (just_opened && v->is_id3_timestamped != 0) {
/* Intercept ID3 tags here, elementary audio streams are required
More information about the ffmpeg-cvslog
mailing list