encoder/flac: use fifo_buffer instead of pcm_buffer

This fixes a buffer corruption bug; pcm_buffer is not designed to be a
persistent buffers, and will discard anything between two consecutive
calls.

3 files changed, 24 insertions, 17 deletions

diff --git a/Makefile.am b/Makefile.am
index 7478ffcc2..6401e3a48 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -994,6 +994,7 @@ test_run_encoder_SOURCES = test/run_encoder.c \
 	src/audio_format.c \
 	src/audio_parser.c \
 	src/pcm_buffer.c \
+	src/fifo_buffer.c src/growing_fifo.c \
 	$(ENCODER_SRC)
 test_run_encoder_CPPFLAGS = $(AM_CPPFLAGS) \
 	$(ENCODER_CFLAGS)
@@ -1057,7 +1058,7 @@ test_run_output_SOURCES = test/run_output.c \
 	src/audio_parser.c \
 	src/timer.c \
 	src/tag.c src/tag_pool.c \
-	src/fifo_buffer.c \
+	src/fifo_buffer.c src/growing_fifo.c \
 	src/page.c \
 	src/socket_util.c \
 	src/output_init.c src/output_list.c \
diff --git a/NEWS b/NEWS
index fc62549fb..b7f0e9f2c 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,8 @@
 ver 0.16.6 (2010/??/??)
 * decoder:
   - fix assertion failure when resuming streams
+* encoder:
+  - flac: fix buffer corruption bug
 * event_pipe: fix WIN32 regression
 * define WINVER in ./configure
 * WIN32: autodetect filesystem encoding
diff --git a/src/encoder/flac_encoder.c b/src/encoder/flac_encoder.c
index c34faad00..6389513ef 100644
--- a/src/encoder/flac_encoder.c
+++ b/src/encoder/flac_encoder.c
@@ -22,6 +22,8 @@
 #include "encoder_plugin.h"
 #include "audio_format.h"
 #include "pcm_buffer.h"
+#include "fifo_buffer.h"
+#include "growing_fifo.h"
 
 #include <assert.h>
 #include <string.h>
@@ -38,8 +40,11 @@ struct flac_encoder {
 
 	struct pcm_buffer expand_buffer;
 
-	struct pcm_buffer buffer;
-	size_t buffer_length;
+	/**
+	 * This buffer will hold encoded data from libFLAC until it is
+	 * picked up with flac_encoder_read().
+	 */
+	struct fifo_buffer *output_buffer;
 };
 
 extern const struct encoder_plugin flac_encoder_plugin;
@@ -140,11 +145,8 @@ flac_write_callback(G_GNUC_UNUSED const FLAC__StreamEncoder *fse,
 {
 	struct flac_encoder *encoder = (struct flac_encoder *) client_data;
 
-	char *buffer = pcm_buffer_get(&encoder->buffer, encoder->buffer_length + bytes);
-
 	//transfer data to buffer
-	memcpy( buffer + encoder->buffer_length, data, bytes);
-	encoder->buffer_length += bytes;
+	growing_fifo_append(&encoder->output_buffer, data, bytes);
 
 	return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;
 }
@@ -156,8 +158,8 @@ flac_encoder_close(struct encoder *_encoder)
 
 	FLAC__stream_encoder_delete(encoder->fse);
 
-	pcm_buffer_deinit(&encoder->buffer);
 	pcm_buffer_deinit(&encoder->expand_buffer);
+	fifo_buffer_free(encoder->output_buffer);
 }
 
 static bool
@@ -201,10 +203,10 @@ flac_encoder_open(struct encoder *_encoder, struct audio_format *audio_format,
 		return false;
 	}
 
-	encoder->buffer_length = 0;
-	pcm_buffer_init(&encoder->buffer);
 	pcm_buffer_init(&encoder->expand_buffer);
 
+	encoder->output_buffer = growing_fifo_new();
+
 	/* this immediatelly outputs data throught callback */
 
 #if !defined(FLAC_API_VERSION_CURRENT) || FLAC_API_VERSION_CURRENT <= 7
@@ -325,16 +327,18 @@ static size_t
 flac_encoder_read(struct encoder *_encoder, void *dest, size_t length)
 {
 	struct flac_encoder *encoder = (struct flac_encoder *)_encoder;
-	char *buffer = pcm_buffer_get(&encoder->buffer, encoder->buffer_length);
-
-	if (length > encoder->buffer_length)
-		length = encoder->buffer_length;
 
-	memcpy(dest, buffer, length);
+	size_t max_length;
+	const char *src = fifo_buffer_read(encoder->output_buffer,
+					   &max_length);
+	if (src == NULL)
+		return 0;
 
-	encoder->buffer_length -= length;
-	memmove(buffer, buffer + length, encoder->buffer_length);
+	if (length > max_length)
+		length = max_length;
 
+	memcpy(dest, src, length);
+	fifo_buffer_consume(encoder->output_buffer, length);
 	return length;
 }