Add --limit-min-bitrate to flac and add test for it

3 files changed, 15 insertions, 0 deletions

diff --git a/src/flac/encode.c b/src/flac/encode.c
index a9b907fa..85279f2a 100644
--- a/src/flac/encode.c
+++ b/src/flac/encode.c
@@ -2147,6 +2147,7 @@ FLAC__bool EncoderSession_init_encoder(EncoderSession *e, encode_options_t optio
 		FLAC__stream_encoder_set_apodization(e->encoder, apodizations);
 	FLAC__stream_encoder_set_total_samples_estimate(e->encoder, e->total_samples_to_encode);
 	FLAC__stream_encoder_set_metadata(e->encoder, (num_metadata > 0)? metadata : 0, num_metadata);
+	FLAC__stream_encoder_set_limit_min_bitrate(e->encoder, options.limit_min_bitrate);
 
 	FLAC__stream_encoder_disable_constant_subframes(e->encoder, options.debug.disable_constant_subframes);
 	FLAC__stream_encoder_disable_fixed_subframes(e->encoder, options.debug.disable_fixed_subframes);
diff --git a/src/flac/encode.h b/src/flac/encode.h
index b98bef6b..c0f36296 100644
--- a/src/flac/encode.h
+++ b/src/flac/encode.h
@@ -85,6 +85,7 @@ typedef struct {
 	FLAC__bool ignore_chunk_sizes;
 	FLAC__bool sector_align;
 	FLAC__bool error_on_compression_fail;
+	FLAC__bool limit_min_bitrate;
 
 	FLAC__StreamMetadata *vorbis_comment;
 	FLAC__StreamMetadata *pictures[64];
diff --git a/src/flac/main.c b/src/flac/main.c
index 2946168f..360b2fdd 100644
--- a/src/flac/main.c
+++ b/src/flac/main.c
@@ -168,6 +168,7 @@ static struct share__option long_options_[] = {
 	{ "sign"                      , share__required_argument, 0, 0 },
 	{ "input-size"                , share__required_argument, 0, 0 },
 	{ "error-on-compression-fail" , share__no_argument, 0, 0 },
+	{ "limit-min-bitrate"         , share__no_argument, 0, 0 },
 
 	/*
 	 * analysis options
@@ -268,6 +269,7 @@ static struct {
 	FLAC__bool cued_seekpoints;
 	FLAC__bool channel_map_none; /* --channel-map=none specified, eventually will expand to take actual channel map */
 	FLAC__bool error_on_compression_fail;
+	FLAC__bool limit_min_bitrate;
 
 	uint32_t num_files;
 	char **filenames;
@@ -597,6 +599,7 @@ FLAC__bool init_options(void)
 	option_values.cued_seekpoints = true;
 	option_values.channel_map_none = false;
 	option_values.error_on_compression_fail = false;
+	option_values.limit_min_bitrate = false;
 
 	option_values.num_files = 0;
 	option_values.filenames = 0;
@@ -825,6 +828,9 @@ int parse_option(int short_option, const char *long_option, const char *option_a
 		else if(0 == strcmp(long_option, "residual-text")) {
 			option_values.aopts.do_residual_text = true;
 		}
+		else if(0 == strcmp(long_option, "limit-min-bitrate")) {
+			option_values.limit_min_bitrate = true;
+		}
 		/*
 		 * negatives
 		 */
@@ -1289,6 +1295,7 @@ void show_help(void)
 	printf("  -p, --qlp-coeff-precision-search   Exhaustively search LP coeff quantization\n");
 	printf("  -q, --qlp-coeff-precision=#        Specify precision in bits\n");
 	printf("  -r, --rice-partition-order=[#,]#   Set [min,]max residual partition order\n");
+	printf("      --limit-min-bitrate            Limit minimum bitrate (for streaming)\n");
 	printf("format options:\n");
 	printf("      --force-raw-format       Treat input or output as raw samples\n");
 	printf("      --force-aiff-format      Force decoding to AIFF format\n");
@@ -1618,6 +1625,11 @@ void show_explain(void)
 	printf("                                     (# is 0 to 15 inclusive; min defaults to 0;\n");
 	printf("                                     the default is -r 0; above 4 does not\n");
 	printf("                                     usually help much)\n");
+	printf("      --limit-min-bitrate            Limit minimum bitrate by not allowing frames\n");
+	printf("                                     consisting of only constant subframes. This\n");
+	printf("                                     ensures a bitrate of at least 1 bit/sample,\n");
+	printf("                                     for example 48kbit/s for 48kHz input. This is\n");
+	printf("                                     mostly beneficial for internet streaming.\n");
 	printf("format options:\n");
 	printf("      --force-raw-format       Force input (when encoding) or output (when\n");
 	printf("                               decoding) to be treated as raw samples\n");
@@ -1926,6 +1938,7 @@ int encode_file(const char *infilename, FLAC__bool is_first_file, FLAC__bool is_
 	encode_options.debug.disable_verbatim_subframes = option_values.debug.disable_verbatim_subframes;
 	encode_options.debug.do_md5 = option_values.debug.do_md5;
 	encode_options.error_on_compression_fail = option_values.error_on_compression_fail;
+	encode_options.limit_min_bitrate = option_values.limit_min_bitrate;
 
 	/* if infilename and outfilename point to the same file, we need to write to a temporary file */
 	if(encode_infile != stdin && grabbag__file_are_same(infilename, outfilename)) {