[FFmpeg-devel] [PATCH] avformat/img2dec: added option -strftime_mkdir to allow directory creation if the strftime pattern include non-existing directories, similarly to how hls muxer does.

[Alexandre Heitor Schmidt]

doc/demuxers.texi: Documented how to use the new parameter.

Usage example:

ffmpeg -i /dev/video0 -strftime 1 -strftime_mkdir 1 "/tmp/%Y/%m/%Y_%m_%d-%H_%M_%S.jpg"
---
 doc/muxers.texi       | 13 +++++++++++++
 libavformat/img2enc.c | 28 +++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/doc/muxers.texi b/doc/muxers.texi
index f6071484ff..1d03fef84b 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -1421,6 +1421,19 @@ overwritten with new images. Default value is 0.
 If set to 1, expand the filename with date and time information from
 @code{strftime()}. Default value is 0.
 
+ at item strftime_mkdir
+Used together with -strftime, if set to 1, it will create all subdirectories
+which are expanded in @var{filename}.
+ at example
+ffmpeg -i /dev/video0 -strftime 1 -strftime_mkdir 1 "/tmp/%Y/%m/%Y_%m_%d-%H_%M_%S.jpg"
+ at end example
+This example will read all frames from /dev/video0 and save each frame into
+ at file{/tmp/%Y_%m/%Y_%m_%d-%H_%M_%S.jpg}, creating the necessary directory
+structure if it doesn't exist. Supposing the current date at the time of the
+image creation is 1978-04-27 15:01:02, the directory @file{/tmp/1978/04}
+would be created - if it didn't existed - prior from saving the output file
+ at file{1978_04_27-15_01_02.jpg} into it.
+
 @item atomic_writing
 Write output to a temporary file, which is renamed to target filename once
 writing is completed. Default is disabled.
diff --git a/libavformat/img2enc.c b/libavformat/img2enc.c
index 9b8ec06cea..238f281467 100644
--- a/libavformat/img2enc.c
+++ b/libavformat/img2enc.c
@@ -44,6 +44,7 @@ typedef struct VideoMuxData {
     char target[4][1024];
     int update;
     int use_strftime;
+    int use_strftime_mkdir;
     int frame_pts;
     const char *muxer;
     int use_rename;
@@ -157,6 +158,22 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
             av_log(s, AV_LOG_ERROR, "Could not get frame filename with strftime\n");
             return AVERROR(EINVAL);
         }
+
+        // whether to create non-existing directory structure
+        if (img->use_strftime_mkdir) {
+            const char *dir;
+            char *fn_copy = av_strdup(filename);
+            if (!fn_copy)
+                return AVERROR(ENOMEM);
+            dir = av_dirname(fn_copy);
+            if (ff_mkdir_p(dir) == -1 && errno != EEXIST) {
+                av_log(s, AV_LOG_ERROR, "Could not create directory %s with use_strftime_mkdir\n", dir);
+                av_freep(&fn_copy);
+                return AVERROR(errno);
+            }
+            av_log(s, AV_LOG_VERBOSE, "Created directory %s\n", dir);
+            av_freep(&fn_copy);
+        }
     } else if (img->frame_pts) {
         if (av_get_frame_filename2(filename, sizeof(filename), s->url, pkt->pts, AV_FRAME_FILENAME_FLAGS_MULTIPLE) < 0) {
             av_log(s, AV_LOG_ERROR, "Cannot write filename by pts of the frames.");
@@ -252,12 +269,13 @@ static int query_codec(enum AVCodecID id, int std_compliance)
 #define OFFSET(x) offsetof(VideoMuxData, x)
 #define ENC AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption muxoptions[] = {
-    { "update",       "continuously overwrite one file", OFFSET(update),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0,       1, ENC },
-    { "start_number", "set first number in the sequence", OFFSET(start_img_number), AV_OPT_TYPE_INT,  { .i64 = 1 }, 0, INT_MAX, ENC },
-    { "strftime",     "use strftime for filename", OFFSET(use_strftime),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
-    { "frame_pts",    "use current frame pts for filename", OFFSET(frame_pts),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
+    { "update",         "continuously overwrite one file", OFFSET(update),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0,       1, ENC },
+    { "start_number",   "set first number in the sequence", OFFSET(start_img_number), AV_OPT_TYPE_INT,  { .i64 = 1 }, 0, INT_MAX, ENC },
+    { "strftime",       "use strftime for filename", OFFSET(use_strftime),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
+    { "strftime_mkdir", "create directory structure for filename, if needed", OFFSET(use_strftime_mkdir),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
+    { "frame_pts",      "use current frame pts for filename", OFFSET(frame_pts),  AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
     { "atomic_writing", "write files atomically (using temporary files and renames)", OFFSET(use_rename), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, ENC },
-    { "protocol_opts", "specify protocol options for the opened files", OFFSET(protocol_opts), AV_OPT_TYPE_DICT, {0}, 0, 0, ENC },
+    { "protocol_opts",  "specify protocol options for the opened files", OFFSET(protocol_opts), AV_OPT_TYPE_DICT, {0}, 0, 0, ENC },
     { NULL },
 };
 
-- 
2.34.1