[libav-devel] [PATCH] ismindex: produce .ismf file

Mika Raento mika.raento at elisa.fi
Wed Sep 3 11:35:36 CEST 2014


This is a non-standard file that maps the MSS segment names to offsets
in the ISMV file. This can be used to build a custom MSS streaming
server without splitting the ISMV into separate files.
---
 tools/ismindex.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 68 insertions(+), 13 deletions(-)

diff --git a/tools/ismindex.c b/tools/ismindex.c
index a6a9763..47846bd 100644
--- a/tools/ismindex.c
+++ b/tools/ismindex.c
@@ -23,7 +23,9 @@
  * avconv <normal input/transcoding options> -movflags frag_keyframe foo.ismv
  * ismindex -n foo foo.ismv
  * This step creates foo.ism and foo.ismc that is required by IIS for
- * serving it.
+ * serving it. It also creates foo.ismf, which maps fragment names to
+ * start-end offsets in the ismv, for use in your own streaming server
+ * (the .ismf file is not created if -split is given).
  *
  * By adding -path-prefix path/, the produced foo.ism will refer to the
  * files foo.ismv as "path/foo.ismv" - the prefix for the generated ismc
@@ -118,6 +120,21 @@ static int copy_tag(AVIOContext *in, AVIOContext *out, int32_t tag_name)
     return 0;
 }
 
+static int skip_tag(AVIOContext *in, int32_t tag_name)
+{
+    int64_t pos   = avio_tell(in);
+    int32_t size, tag;
+
+    size = avio_rb32(in);
+    tag  = avio_rb32(in);
+    if (tag != tag_name) {
+        fprintf(stderr, "wanted tag %d, got %d", tag_name, tag);
+        return -1;
+    }
+    avio_seek(in, pos + size, SEEK_SET);
+    return 0;
+}
+
 static int write_fragment(const char *filename, AVIOContext *in)
 {
     AVIOContext *out = NULL;
@@ -139,25 +156,62 @@ static int write_fragment(const char *filename, AVIOContext *in)
     return ret;
 }
 
+static int skip_fragment(AVIOContext *in)
+{
+    return (skip_tag(in, MKBETAG('m', 'o', 'o', 'f')) ||
+            skip_tag(in, MKBETAG('m', 'd', 'a', 't')));
+}
+
 static int write_fragments(struct Tracks *tracks, int start_index,
-                           AVIOContext *in, const char *output_prefix)
+                           AVIOContext *in, const char *basename,
+                           int split, const char* output_prefix)
 {
-    char dirname[2048], filename[2048];
-    int i, j;
+    char dirname[2048], filename[2048], idxname[2048];
+    int i, j, ret, fragment_ret;
+    FILE* out;
 
+    out = NULL;
+    ret = 0;
+    if (!split) {
+        snprintf(idxname, sizeof(idxname), "%s%s.ismf", output_prefix, basename);
+        out = fopen(idxname, "w");
+        if (!out) {
+            ret = AVERROR(errno);
+            perror(idxname);
+            goto fail;
+        }
+    }
     for (i = start_index; i < tracks->nb_tracks; i++) {
         struct Track *track = tracks->tracks[i];
         const char *type    = track->is_video ? "video" : "audio";
         snprintf(dirname, sizeof(dirname), "%sQualityLevels(%d)", output_prefix, track->bitrate);
-        mkdir(dirname, 0777);
+        if (split) {
+            if (mkdir(dirname, 0777) == -1) {
+                ret = AVERROR(errno);
+                perror(dirname);
+                goto fail;
+            }
+        }
         for (j = 0; j < track->chunks; j++) {
             snprintf(filename, sizeof(filename), "%s/Fragments(%s=%"PRId64")",
                      dirname, type, track->offsets[j].time);
             avio_seek(in, track->offsets[j].offset, SEEK_SET);
-            write_fragment(filename, in);
+            if (split) {
+                fragment_ret = write_fragment(filename, in);
+            } else {
+                fprintf(out, "%s %"PRId64, filename, avio_tell(in));
+                fragment_ret = skip_fragment(in);
+                fprintf(out, " %"PRId64"\n", avio_tell(in));
+            }
+            if (fragment_ret != 0) {
+                fprintf(stderr, "failed fragment");
+                ret = fragment_ret;
+            }
         }
     }
-    return 0;
+fail:
+    if (out) fclose(out);
+    return ret;
 }
 
 static int read_tfra(struct Tracks *tracks, int start_index, AVIOContext *f)
@@ -217,7 +271,8 @@ fail:
 }
 
 static int read_mfra(struct Tracks *tracks, int start_index,
-                     const char *file, int split, const char *output_prefix)
+                     const char *file, int split, const char *basename,
+                     const char* output_prefix)
 {
     int err = 0;
     const char* err_str = "";
@@ -243,8 +298,8 @@ static int read_mfra(struct Tracks *tracks, int start_index,
         /* Empty */
     }
 
-    if (split)
-        write_fragments(tracks, start_index, f, output_prefix);
+    err = write_fragments(tracks, start_index, f, basename, split, output_prefix);
+    err_str = "error in write_fragments";
 
 fail:
     if (f)
@@ -296,7 +351,7 @@ fail:
 }
 
 static int handle_file(struct Tracks *tracks, const char *file, int split,
-                       const char *output_prefix)
+                       const char *basename, const char* output_prefix)
 {
     AVFormatContext *ctx = NULL;
     int err = 0, i, orig_tracks = tracks->nb_tracks;
@@ -404,7 +459,7 @@ static int handle_file(struct Tracks *tracks, const char *file, int split,
 
     avformat_close_input(&ctx);
 
-    err = read_mfra(tracks, orig_tracks, file, split, output_prefix);
+    err = read_mfra(tracks, orig_tracks, file, split, basename, output_prefix);
 
 fail:
     if (ctx)
@@ -607,7 +662,7 @@ int main(int argc, char **argv)
         } else if (argv[i][0] == '-') {
             return usage(argv[0], 1);
         } else {
-            if (handle_file(&tracks, argv[i], split, output_prefix))
+            if (handle_file(&tracks, argv[i], split, basename, output_prefix))
                 return 1;
         }
     }
-- 
1.8.5.2 (Apple Git-48)



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