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authorMax Kellermann <max@duempel.org>2013-08-06 08:35:02 +0200
committerMax Kellermann <max@duempel.org>2013-08-06 09:13:28 +0200
commit3f04a4d635bf217126298df5e1c2d95bce94f764 (patch)
tree97c5a9fc980887216271c6159c3d4219f0d6bf45 /src
parent17c8e839b6eedf2ab02543bca5500e97c82c457d (diff)
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encoder/lame: dynamic output buffer
Diffstat (limited to 'src')
-rw-r--r--src/encoder/LameEncoderPlugin.cxx22
-rw-r--r--src/util/AllocatedArray.hxx189
2 files changed, 207 insertions, 4 deletions
diff --git a/src/encoder/LameEncoderPlugin.cxx b/src/encoder/LameEncoderPlugin.cxx
index 2dbd6a0df..2e988d89a 100644
--- a/src/encoder/LameEncoderPlugin.cxx
+++ b/src/encoder/LameEncoderPlugin.cxx
@@ -21,6 +21,8 @@
#include "LameEncoderPlugin.hxx"
#include "EncoderAPI.hxx"
#include "AudioFormat.hxx"
+#include "util/AllocatedArray.hxx"
+#include "util/Manual.hxx"
#include <lame/lame.h>
@@ -38,7 +40,7 @@ struct LameEncoder final {
lame_global_flags *gfp;
- unsigned char output_buffer[32768];
+ Manual<AllocatedArray<unsigned char>> output_buffer;
size_t output_buffer_length, output_buffer_position;
LameEncoder():encoder(lame_encoder_plugin) {}
@@ -209,6 +211,8 @@ lame_encoder_open(Encoder *_encoder, AudioFormat &audio_format,
return false;
}
+ encoder->output_buffer.Construct();
+
encoder->output_buffer_length = 0;
encoder->output_buffer_position = 0;
@@ -221,6 +225,7 @@ lame_encoder_close(Encoder *_encoder)
LameEncoder *encoder = (LameEncoder *)_encoder;
lame_close(encoder->gfp);
+ encoder->output_buffer.Destruct();
}
static bool
@@ -236,14 +241,22 @@ lame_encoder_write(Encoder *_encoder,
const unsigned num_frames =
length / encoder->audio_format.GetFrameSize();
+ const unsigned num_samples =
+ length / encoder->audio_format.GetSampleSize();
+
+ /* worst-case formula according to LAME documentation */
+ const size_t output_buffer_size = 5 * num_samples / 4 + 7200;
+ encoder->output_buffer->GrowDiscard(output_buffer_size);
+
+ const auto output_buffer = encoder->output_buffer->begin();
/* this is for only 16-bit audio */
int bytes_out = lame_encode_buffer_interleaved(encoder->gfp,
const_cast<short *>(src),
num_frames,
- encoder->output_buffer,
- sizeof(encoder->output_buffer));
+ output_buffer,
+ output_buffer_size);
if (bytes_out < 0) {
g_set_error(error, lame_encoder_quark(), 0,
@@ -269,7 +282,8 @@ lame_encoder_read(Encoder *_encoder, void *dest, size_t length)
if (length > remainning)
length = remainning;
- memcpy(dest, encoder->output_buffer + encoder->output_buffer_position,
+ memcpy(dest,
+ encoder->output_buffer->begin() + encoder->output_buffer_position,
length);
encoder->output_buffer_position += length;
diff --git a/src/util/AllocatedArray.hxx b/src/util/AllocatedArray.hxx
new file mode 100644
index 000000000..e3bcf8c64
--- /dev/null
+++ b/src/util/AllocatedArray.hxx
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2010 Max Kellermann <max@duempel.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef ALLOCATED_ARRAY_HPP
+#define ALLOCATED_ARRAY_HPP
+
+#include "gcc.h"
+
+#include <assert.h>
+#include <algorithm>
+
+/**
+ * An array allocated on the heap with a length determined at runtime.
+ */
+template<class T>
+class AllocatedArray {
+public:
+ typedef size_t size_type;
+
+protected:
+ size_type the_size;
+ T *restrict data;
+
+public:
+ typedef T *iterator;
+ typedef const T *const_iterator;
+
+public:
+ constexpr AllocatedArray():the_size(0), data(nullptr) {}
+
+ explicit AllocatedArray(size_type _size)
+ :the_size(_size), data(new T[the_size]) {
+ assert(size() == 0 || data != nullptr);
+ }
+
+ explicit AllocatedArray(const AllocatedArray &other)
+ :the_size(other.size()), data(new T[the_size]) {
+ assert(size() == 0 || data != nullptr);
+ assert(other.size() == 0 || other.data != nullptr);
+
+ std::copy(other.data, other.data + the_size, data);
+ }
+
+ explicit AllocatedArray(AllocatedArray &&other)
+ :the_size(other.the_size), data(other.data) {
+ other.the_size = 0;
+ other.data = nullptr;
+ }
+
+ ~AllocatedArray() {
+ delete[] data;
+ }
+
+ AllocatedArray &operator=(const AllocatedArray &other) {
+ assert(size() == 0 || data != nullptr);
+ assert(other.size() == 0 || other.data != nullptr);
+
+ if (&other == this)
+ return *this;
+
+ ResizeDiscard(other.size());
+ std::copy(other.begin(), other.end(), data);
+ return *this;
+ }
+
+ AllocatedArray &operator=(AllocatedArray &&other) {
+ std::swap(the_size, other.the_size);
+ std::swap(data, other.data);
+ return *this;
+ }
+
+ /**
+ * Returns true if no memory was allocated so far.
+ */
+ constexpr bool empty() const {
+ return the_size == 0;
+ }
+
+ /**
+ * Returns the number of allocated elements.
+ */
+ constexpr size_type size() const {
+ return the_size;
+ }
+
+ /**
+ * Returns one element. No bounds checking.
+ */
+ T &operator[](size_type i) {
+ assert(i < size());
+
+ return data[i];
+ }
+
+ /**
+ * Returns one constant element. No bounds checking.
+ */
+ const T &operator[](size_type i) const {
+ assert(i < size());
+
+ return data[i];
+ }
+
+ iterator begin() {
+ return data;
+ }
+
+ constexpr const_iterator begin() const {
+ return data;
+ }
+
+ iterator end() {
+ return data + the_size;
+ }
+
+ constexpr const_iterator end() const {
+ return data + the_size;
+ }
+
+ /**
+ * Resizes the array, discarding old data.
+ */
+ void ResizeDiscard(size_type _size) {
+ if (_size == the_size)
+ return;
+
+ delete[] data;
+ the_size = _size;
+ data = new T[the_size];
+
+ assert(size() == 0 || data != nullptr);
+ }
+
+ /**
+ * Grows the array to the specified size, discarding old data.
+ * Similar to ResizeDiscard(), but will never shrink the array to
+ * avoid expensive heap operations.
+ */
+ void GrowDiscard(size_type _size) {
+ if (_size > the_size)
+ ResizeDiscard(_size);
+ }
+
+ /**
+ * Grows the array to the specified size, preserving the value of a
+ * range of elements, starting from the beginning.
+ */
+ void GrowPreserve(size_type _size, size_type preserve) {
+ if (_size <= the_size)
+ return;
+
+ T *new_data = new T[_size];
+ assert(_size == 0 || new_data != nullptr);
+
+ std::move(data, data + preserve, new_data);
+
+ delete[] data;
+ data = new_data;
+ the_size = _size;
+ }
+};
+
+#endif