Voicemail: get correct duration when copying file to vm

Changes made during format improvements resulted in the
recording to voicemail option 'm' of the MixMonitor app
writing a zero length duration in the msgXXXX.txt file.

This change introduces a new function ast_ratestream(),
which provides the sample rate of the format associated
with the stream, and updates the app_voicemail function
for ast_app_copy_recording_to_vm to calculate the right
duration.

Review: https://reviewboard.asterisk.org/r/3996/
ASTERISK-24328 #close



git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@423192 65c4cc65-6c06-0410-ace0-fbb531ad65f3

apps/app_voicemail.c

@@ -6130,15 +6130,11 @@ static int msg_create_from_file(struct ast_vm_recording_data *recdata)
 	if ((recording_fs = ast_readfile(recdata->recording_file, recdata->recording_ext, NULL, 0, 0, VOICEMAIL_DIR_MODE))) {
 		if (!ast_seekstream(recording_fs, 0, SEEK_END)) {
 			long framelength = ast_tellstream(recording_fs);
-			struct ast_format *result;
-			/* XXX This use of ast_getformatbyname seems incorrect here. The file extension does not necessarily correspond
-			 * to the name of the format. For instance, if "raw" were passed in, I don't think ast_getformatbyname would
-			 * find the slinear format
-			 */
-			result = ast_format_cache_get(recdata->recording_ext);
-			if (result) {
-				duration = (int) (framelength / ast_format_get_sample_rate(result));
-				ao2_ref(result, -1);
+			int sample_rate = ast_ratestream(recording_fs);
+			if (sample_rate) {
+				duration = (int) (framelength / sample_rate);
+			} else {
+				ast_log(LOG_ERROR,"Unable to determine sample rate of recording %s\n", recdata->recording_file);
 			}
 		}
 	}

include/asterisk/file.h

@@ -350,6 +350,13 @@ int ast_stream_rewind(struct ast_filestream *fs, off_t ms);
  */
 off_t ast_tellstream(struct ast_filestream *fs);
 
+/*!
+ * \brief Return the sample rate of the stream's format
+ * \param fs fs to act on
+ * \return sample rate in Hz
+ */
+int ast_ratestream(struct ast_filestream *fs);
+
 /*! 
  * \brief Read a frame from a filestream 
  * \param s ast_filestream to act on

main/file.c

@@ -1026,6 +1026,11 @@ off_t ast_tellstream(struct ast_filestream *fs)
 	return fs->fmt->tell(fs);
 }
 
+int ast_ratestream(struct ast_filestream *fs)
+{
+	return ast_format_get_sample_rate(fs->fmt->format);
+}
+
 int ast_stream_fastforward(struct ast_filestream *fs, off_t ms)
 {
 	return ast_seekstream(fs, ms * DEFAULT_SAMPLES_PER_MS, SEEK_CUR);