Re: [FFmpeg-devel] [PATCH 01/10] avformat/segment: Add segment_write_temp option

[Marton Balint]

On Fri, 13 Jun 2025, softworkz wrote:

From: softworkz <softwo...@hotmail.com>

Allows to write segments as temp files (.tmp) which
are renamed on completion.

Signed-off-by: softworkz <softwo...@hotmail.com>
---
libavformat/segment.c | 30 +++++++++++++++++++++++++++---
1 file changed, 27 insertions(+), 3 deletions(-)

diff --git a/libavformat/segment.c b/libavformat/segment.c
index 65323ec678..04e973a198 100644
--- a/libavformat/segment.c
+++ b/libavformat/segment.c
@@ -121,6 +121,7 @@ typedef struct SegmentContext {
    int   break_non_keyframes;
    int   write_empty;

+    int segment_write_temp; ///< write segments as temp files and rename on 
completion
    int use_rename;
    char temp_list_filename[1024];

@@ -226,6 +227,15 @@ static int set_segment_filename(AVFormatContext *s)
             seg->entry_prefix ? seg->entry_prefix : "",
             av_basename(oc->url));

+    // Write segment as a temp file and rename on completion
+    if(seg->segment_write_temp) {
+        av_strlcatf(buf, sizeof(buf), ".tmp");
+        char *temp_name = av_strdup(buf);
+        if (!temp_name)
+            return AVERROR(ENOMEM);

You should use av_asprintf() directly instead of strlcatf() + av_strdup()

+        ff_format_set_url(oc, temp_name);
+    }
+
    return 0;
}

@@ -372,7 +382,7 @@ static int segment_end(AVFormatContext *s, int 
write_trailer, int is_last)
            SegmentListEntry *entry = av_mallocz(sizeof(*entry));
            if (!entry) {
                ret = AVERROR(ENOMEM);
-                goto end;
+                goto fail;
            }

            /* append new element */
@@ -393,7 +403,7 @@ static int segment_end(AVFormatContext *s, int 
write_trailer, int is_last)
            }

            if ((ret = segment_list_open(s)) < 0)
-                goto end;
+                goto fail;
            for (entry = seg->segment_list_entries; entry; entry = entry->next)
                segment_list_print_entry(seg->list_pb, seg->list_type, entry, 
s);
            if (seg->list_type == LIST_TYPE_M3U8 && is_last)
@@ -450,7 +460,20 @@ static int segment_end(AVFormatContext *s, int 
write_trailer, int is_last)
        }
    }

-end:
+    ff_format_io_close(oc, &oc->pb);
+
+    // Now rename the .tmp file to its actual name.
+    if (seg->segment_write_temp) {
+        char *final_filename = av_strndup(oc->url, strlen(oc->url) - 4);
+        if (!final_filename)
+            return AVERROR(ENOMEM);

goto fail?

+        ret = ff_rename(oc->url, final_filename, s);
+        av_free(final_filename);
+    }
+
+    return ret;
+
+fail:
    ff_format_io_close(oc, &oc->pb);

    return ret;
@@ -1075,6 +1098,7 @@ static const AVOption options[] = {
    { "reset_timestamps", "reset timestamps at the beginning 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_write_temp", "write segments as temp files (.tmp) and rename on 
completion", OFFSET(segment_write_temp), AV_OPT_TYPE_BOOL,   {.i64 = 0}, 0, 1, E },
    { NULL },
};

Regards,
Marton
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".