@@ -1390,6 +1390,23 @@ argument must be a time duration specification, and defaults to 0.
If enabled, write an empty segment if there are no packets during the period a
segment would usually span. Otherwise, the segment will be filled with the next
packet written. Defaults to @code{0}.
+
+@item individual_header_trailer @var{1|0}
+Write each segment as an individual distinct file in the underlying format.
+When this is set to @code{0}, the segments are treated as a single continuous
+stream. When set to @code{1} (the default), each individual segment receives
+a header and trailer, so they can be played independently.
+
+@item segment_header_filename @var{name}
+Write the global header to a separate file. Requires
+@var{individual_header_trailer} to be @code{0}. If not set, the global header
+will be written to the first file along with actual segment data.
+
+@item segment_seekback @var{1|0}
+Allow the muxer to seek back and overwrite data from previous segments. Requires
+@var{individual_header_trailer} to be @code{0}. If set to @code{0} (the default),
+the underlying muxer will be unable to seek back into previous segments, so they
+can be relied upon not to change once written.
@end table
@subsection Examples
@@ -51,8 +51,10 @@ typedef struct SegmentListEntry {
int64_t start_pts;
int64_t offset_pts;
char *filename;
+ char *full_filename;
struct SegmentListEntry *next;
int64_t last_duration;
+ size_t start_offset;
} SegmentListEntry;
typedef enum {
@@ -125,7 +127,13 @@ typedef struct SegmentContext {
SegmentListEntry cur_entry;
SegmentListEntry *segment_list_entries;
+ SegmentListEntry *segment_list_entries_all;
SegmentListEntry *segment_list_entries_end;
+ SegmentListEntry *segment_list_entry_writing;
+ int seekback; ///< allow seeking back to previous segments
+ AVIOContext *cur_pb; ///< current segment put-byte context
+ size_t write_offset;
+ size_t max_offset;
} SegmentContext;
static void print_csv_escaped_str(AVIOContext *ctx, const char *str)
@@ -144,6 +152,123 @@ static void print_csv_escaped_str(AVIOContext *ctx, const char *str)
avio_w8(ctx, '"');
}
+static int64_t virtual_seek(void *priv, int64_t target, int whence)
+{
+ AVFormatContext *s = priv;
+ SegmentContext *seg = s->priv_data;
+ SegmentListEntry *it, *current = NULL;
+ int64_t offset = target;
+ int64_t ret;
+
+ if (whence != SEEK_SET)
+ return AVERROR(EINVAL);
+ if (offset < 0)
+ return AVERROR(EINVAL);
+
+ if (offset >= seg->max_offset) {
+ ff_format_io_close(s, &seg->cur_pb);
+ seg->write_offset = offset;
+ return offset;
+ }
+
+ if (seg->cur_entry.start_offset <= offset) {
+ current = &seg->cur_entry;
+ } else {
+ for (it = seg->segment_list_entries_all; it; it = it->next) {
+ if (it->start_offset <= offset)
+ current = it;
+ else if (it->start_offset > offset)
+ break;
+ }
+ }
+
+ offset -= current->start_offset;
+
+ if (current != seg->segment_list_entry_writing) {
+ int is_seekback = (current != &seg->cur_entry) && seg->segment_list_entries;
+ char *new_filename;
+ AVIOContext *new_ctx = NULL;
+ AVDictionary *options = NULL;
+
+ if (!seg->seekback && is_seekback)
+ return AVERROR(EINVAL);
+
+ new_filename = current->full_filename;
+
+ if (new_filename) {
+ if (is_seekback)
+ av_dict_set_int(&options, "truncate", 0, 0);
+ if ((ret = s->io_open(s, &new_ctx, new_filename, AVIO_FLAG_WRITE, &options)) < 0) {
+ av_log(s, AV_LOG_ERROR, "Failed to seek into segment '%s'\n", new_filename);
+ return ret;
+ }
+ }
+
+ ff_format_io_close(s, &seg->cur_pb);
+ seg->cur_pb = new_ctx;
+ seg->segment_list_entry_writing = current;
+ }
+
+ if (seg->cur_pb)
+ if ((ret = avio_seek(seg->cur_pb, offset, SEEK_SET)) < 0)
+ return ret;
+
+ seg->write_offset = offset;
+
+ return target;
+}
+
+static int virtual_write(void *priv, uint8_t *buf, int buf_size)
+{
+ AVFormatContext *s = priv;
+ SegmentContext *seg = s->priv_data;
+ int ret = 0;
+ int written = 0;
+
+ while (written < buf_size) {
+ SegmentListEntry *cur = seg->segment_list_entry_writing;
+ size_t start = cur->start_offset + seg->write_offset;
+ SegmentListEntry *next = cur->next ? cur->next : (cur == &seg->cur_entry ? NULL : &seg->cur_entry);
+ size_t end = next ? next->start_offset : SIZE_MAX;
+ int to_write = FFMIN(end - start, buf_size - written);
+ if (seg->cur_pb)
+ avio_write(seg->cur_pb, buf, to_write);
+ buf += to_write;
+ written += to_write;
+ seg->write_offset += to_write;
+ if (written < buf_size)
+ if ((ret = virtual_seek(s, end, SEEK_SET)) < 0)
+ return ret;
+ }
+
+ return written;
+}
+
+static void virtual_close(AVFormatContext *s)
+{
+ SegmentContext *seg = s->priv_data;
+ ff_format_io_close(s, &seg->cur_pb);
+ av_freep(&seg->avf->pb->buffer);
+ av_freep(&seg->avf->pb);
+}
+
+static int open_virtual_ctx(AVFormatContext *s, AVIOContext **ctx)
+{
+ SegmentContext *seg = s->priv_data;
+ int buf_size = 32768;
+ uint8_t *buf = av_malloc(buf_size);
+ if (!buf)
+ return AVERROR(ENOMEM);
+ *ctx = avio_alloc_context(buf, buf_size, AVIO_FLAG_WRITE, s, NULL,
+ virtual_write, virtual_seek);
+ if (!*ctx) {
+ av_free(buf);
+ return AVERROR(ENOMEM);
+ }
+ (*ctx)->seekable = seg->seekback;
+ return virtual_seek(s, 0, SEEK_SET);
+}
+
static int segment_mux_init(AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
@@ -193,7 +318,6 @@ static int set_segment_filename(AVFormatContext *s)
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
size_t size;
- int ret;
if (seg->segment_idx_wrap)
seg->segment_idx %= seg->segment_idx_wrap;
@@ -212,13 +336,18 @@ static int set_segment_filename(AVFormatContext *s)
return AVERROR(EINVAL);
}
+ seg->cur_entry.full_filename = av_strdup(oc->filename);
+ if (!seg->cur_entry.full_filename)
+ return AVERROR(ENOMEM);
+
/* copy modified name in list entry */
size = strlen(av_basename(oc->filename)) + 1;
if (seg->entry_prefix)
size += strlen(seg->entry_prefix);
- if ((ret = av_reallocp(&seg->cur_entry.filename, size)) < 0)
- return ret;
+ seg->cur_entry.filename = av_mallocz(size);
+ if (!seg->cur_entry.filename)
+ return AVERROR(ENOMEM);
snprintf(seg->cur_entry.filename, size, "%s%s",
seg->entry_prefix ? seg->entry_prefix : "",
av_basename(oc->filename));
@@ -247,12 +376,16 @@ static int segment_start(AVFormatContext *s, int write_header)
if ((err = set_segment_filename(s)) < 0)
return err;
- if ((err = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0) {
- av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", oc->filename);
- return err;
+ if (seg->individual_header_trailer) {
+ if ((err = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0) {
+ av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", oc->filename);
+ return err;
+ }
+ } else {
+ seg->cur_entry.start_offset += seg->write_offset;
+ if ((err = virtual_seek(s, seg->cur_entry.start_offset, SEEK_SET)) < 0)
+ return err;
}
- if (!seg->individual_header_trailer)
- oc->pb->seekable = 0;
if (oc->oformat->priv_class && oc->priv_data)
av_opt_set(oc->priv_data, "mpegts_flags", "+resend_headers", 0);
@@ -344,6 +477,7 @@ static int segment_end(AVFormatContext *s, int write_trailer, int is_last)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
+ SegmentListEntry *entry;
int ret = 0;
AVTimecode tc;
AVRational rate;
@@ -360,29 +494,27 @@ static int segment_end(AVFormatContext *s, int write_trailer, int is_last)
av_log(s, AV_LOG_ERROR, "Failure occurred when ending segment '%s'\n",
oc->filename);
- if (seg->list) {
- if (seg->list_size || seg->list_type == LIST_TYPE_M3U8) {
- SegmentListEntry *entry = av_mallocz(sizeof(*entry));
- if (!entry) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
+ entry = av_mallocz(sizeof(*entry));
+ if (!entry) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+
+ /* append new element */
+ memcpy(entry, &seg->cur_entry, sizeof(*entry));
+ if (!seg->segment_list_entries)
+ seg->segment_list_entries_all->next = seg->segment_list_entries = entry;
+ else
+ seg->segment_list_entries_end->next = entry;
+ seg->segment_list_entries_end = entry;
- /* append new element */
- memcpy(entry, &seg->cur_entry, sizeof(*entry));
- entry->filename = av_strdup(entry->filename);
- if (!seg->segment_list_entries)
- seg->segment_list_entries = seg->segment_list_entries_end = entry;
- else
- seg->segment_list_entries_end->next = entry;
- seg->segment_list_entries_end = entry;
+ seg->segment_list_entry_writing = NULL;
+ if (seg->list) {
+ if (seg->list_size || seg->list_type == LIST_TYPE_M3U8) {
/* drop first item */
if (seg->list_size && seg->segment_count >= seg->list_size) {
- entry = seg->segment_list_entries;
seg->segment_list_entries = seg->segment_list_entries->next;
- av_freep(&entry->filename);
- av_freep(&entry);
}
if ((ret = segment_list_open(s)) < 0)
@@ -428,7 +560,8 @@ static int segment_end(AVFormatContext *s, int write_trailer, int is_last)
}
end:
- ff_format_io_close(oc, &oc->pb);
+ if (seg->individual_header_trailer)
+ ff_format_io_close(oc, &oc->pb);
return ret;
}
@@ -550,26 +683,6 @@ end:
return ret;
}
-static int open_null_ctx(AVIOContext **ctx)
-{
- int buf_size = 32768;
- uint8_t *buf = av_malloc(buf_size);
- if (!buf)
- return AVERROR(ENOMEM);
- *ctx = avio_alloc_context(buf, buf_size, AVIO_FLAG_WRITE, NULL, NULL, NULL, NULL);
- if (!*ctx) {
- av_free(buf);
- return AVERROR(ENOMEM);
- }
- return 0;
-}
-
-static void close_null_ctxp(AVIOContext **pb)
-{
- av_freep(&(*pb)->buffer);
- av_freep(pb);
-}
-
static int select_reference_stream(AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
@@ -627,9 +740,12 @@ static int select_reference_stream(AVFormatContext *s)
return 0;
}
-static void seg_free_context(SegmentContext *seg)
+static void seg_free_context(AVFormatContext *s)
{
+ SegmentContext *seg = s->priv_data;
ff_format_io_close(seg->avf, &seg->list_pb);
+ if (!seg->individual_header_trailer)
+ virtual_close(s);
avformat_free_context(seg->avf);
seg->avf = NULL;
}
@@ -642,6 +758,14 @@ static int seg_init(AVFormatContext *s)
int ret;
int i;
+ seg->max_offset = SIZE_MAX;
+
+ if (seg->write_header_trailer && !seg->header_filename) {
+ seg->cur_entry.start_offset = 0;
+ } else {
+ seg->cur_entry.start_offset = SIZE_MAX;
+ }
+
seg->segment_count = 0;
if (!seg->write_header_trailer)
seg->individual_header_trailer = 0;
@@ -743,17 +867,27 @@ static int seg_init(AVFormatContext *s)
goto fail;
oc = seg->avf;
- if (seg->write_header_trailer) {
- if ((ret = s->io_open(s, &oc->pb,
- seg->header_filename ? seg->header_filename : oc->filename,
- AVIO_FLAG_WRITE, NULL)) < 0) {
+ seg->segment_list_entries_all = av_mallocz(sizeof(*seg->segment_list_entries_all));
+ if (!seg->segment_list_entries_all) {
+ ret = ENOMEM;
+ goto fail;
+ }
+
+ if (seg->header_filename) {
+ seg->segment_list_entries_all->full_filename = av_strdup(seg->header_filename);
+ if (!seg->segment_list_entries_all->full_filename) {
+ ret = ENOMEM;
+ goto fail;
+ }
+ }
+
+ if (seg->individual_header_trailer) {
+ if ((ret = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0) {
av_log(s, AV_LOG_ERROR, "Failed to open segment '%s'\n", oc->filename);
goto fail;
}
- if (!seg->individual_header_trailer)
- oc->pb->seekable = 0;
} else {
- if ((ret = open_null_ctx(&oc->pb)) < 0)
+ if ((ret = open_virtual_ctx(s, &oc->pb)) < 0)
goto fail;
}
@@ -783,22 +917,17 @@ static int seg_init(AVFormatContext *s)
s->avoid_negative_ts = 1;
if (!seg->write_header_trailer || seg->header_filename) {
- if (seg->header_filename) {
- av_write_frame(oc, NULL);
- ff_format_io_close(oc, &oc->pb);
- } else {
- close_null_ctxp(&oc->pb);
- }
- if ((ret = oc->io_open(oc, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0)
+ av_write_frame(oc, NULL);
+ seg->cur_entry.start_offset = seg->write_offset;
+ if ((ret = virtual_seek(s, seg->write_offset, SEEK_SET)) < 0)
goto fail;
- if (!seg->individual_header_trailer)
- oc->pb->seekable = 0;
+ ret = 0;
}
fail:
av_dict_free(&options);
if (ret < 0)
- seg_free_context(seg);
+ seg_free_context(s);
return ret;
}
@@ -914,7 +1043,7 @@ fail:
}
if (ret < 0)
- seg_free_context(seg);
+ seg_free_context(s);
return ret;
}
@@ -932,13 +1061,17 @@ static int seg_write_trailer(struct AVFormatContext *s)
if (!seg->write_header_trailer) {
if ((ret = segment_end(s, 0, 1)) < 0)
goto fail;
- if ((ret = open_null_ctx(&oc->pb)) < 0)
- goto fail;
+
+ seg->max_offset = seg->cur_entry.start_offset + seg->write_offset;
+ virtual_seek(oc->pb, seg->max_offset, SEEK_SET);
ret = av_write_trailer(oc);
- close_null_ctxp(&oc->pb);
} else {
ret = segment_end(s, 1, 1);
}
+
+ if (!seg->individual_header_trailer)
+ virtual_close(s);
+
fail:
if (seg->list)
ff_format_io_close(s, &seg->list_pb);
@@ -947,11 +1080,11 @@ fail:
av_opt_free(seg);
av_freep(&seg->times);
av_freep(&seg->frames);
- av_freep(&seg->cur_entry.filename);
- cur = seg->segment_list_entries;
+ cur = seg->segment_list_entries_all;
while (cur) {
next = cur->next;
+ av_freep(&cur->full_filename);
av_freep(&cur->filename);
av_free(cur);
cur = next;
@@ -1005,6 +1138,7 @@ static const AVOption options[] = {
{ "reset_timestamps", "reset timestamps at the begin of each segment", OFFSET(reset_timestamps), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
{ "initial_offset", "set initial timestamp offset", OFFSET(initial_offset), AV_OPT_TYPE_DURATION, {.i64 = 0}, -INT64_MAX, INT64_MAX, E },
{ "write_empty_segments", "allow writing empty 'filler' segments", OFFSET(write_empty), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
+ { "segment_seekback", "allow seeking back to previous segments", OFFSET(seekback), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E },
{ NULL },
};
@@ -33,7 +33,7 @@
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 57
#define LIBAVFORMAT_VERSION_MINOR 51
-#define LIBAVFORMAT_VERSION_MICRO 102
+#define LIBAVFORMAT_VERSION_MICRO 103
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \