fix crash when copy'ing latent plugins

[ardour.git] / libs / ardour / ardour / audio_buffer.h

diff --git a/libs/ardour/ardour/audio_buffer.h b/libs/ardour/ardour/audio_buffer.h
index a32e679b692ca59816a652eb8638270d86730ecf..9a9653b2c99620690317d98a2bff309af84bd6b7 100644 (file)
--- a/libs/ardour/ardour/audio_buffer.h
+++ b/libs/ardour/ardour/audio_buffer.h
@@ -33,9 +33,18 @@ public:
        AudioBuffer(size_t capacity);
        ~AudioBuffer();
 
+       /** silence buffer
+        * @param len number of samples to clear
+        * @laram offset start offset
+        */
        void silence (framecnt_t len, framecnt_t offset = 0);
 
-       /** Read @a len frames @a src starting at @a src_offset into self starting at @ dst_offset*/
+       /** Copy samples from src array starting at src_offset into self starting at dst_offset
+        * @param src array to read from
+        * @param len number of samples to copy
+        * @param dst_offset offset in destination buffer
+        * @param src_offset start offset in src buffer
+        */
        void read_from (const Sample* src, framecnt_t len, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                assert(src != 0);
                assert(_capacity > 0);
@@ -45,7 +54,7 @@ public:
                _written = true;
        }
 
-        void read_from_with_gain (const Sample* src, framecnt_t len, gain_t gain, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
+       void read_from_with_gain (const Sample* src, framecnt_t len, gain_t gain, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                assert(src != 0);
                assert(_capacity > 0);
                assert(len <= _capacity);
@@ -57,12 +66,17 @@ public:
                _written = true;
        }
 
-       /** Read @a len frames @a src starting at @a src_offset into self starting at @ dst_offset*/
+       /** Copy samples from src buffer starting at src_offset into self starting at dst_offset
+        * @param src buffer to read from
+        * @param len number of samples to copy
+        * @param dst_offset offset in destination buffer
+        * @param src_offset start offset in src buffer
+        */
        void read_from (const Buffer& src, framecnt_t len, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                assert(&src != this);
                assert(_capacity > 0);
                assert(src.type() == DataType::AUDIO);
-               assert(len <= _capacity);
+               assert(dst_offset + len <= _capacity);
                assert( src_offset <= ((framecnt_t) src.capacity()-len));
                memcpy(_data + dst_offset, ((const AudioBuffer&)src).data() + src_offset, sizeof(Sample) * len);
                if (dst_offset == 0 && src_offset == 0 && len == _capacity) {
@@ -73,14 +87,14 @@ public:
                _written = true;
        }
 
-       /** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
+       /** Accumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
        void merge_from (const Buffer& src, framecnt_t len, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                const AudioBuffer* ab = dynamic_cast<const AudioBuffer*>(&src);
                assert (ab);
                accumulate_from (*ab, len, dst_offset, src_offset);
        }
 
-       /** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
+       /** Accumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
        void accumulate_from (const AudioBuffer& src, framecnt_t len, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                assert(_capacity > 0);
                assert(len <= _capacity);
@@ -94,7 +108,7 @@ public:
                _written = true;
        }
 
-       /** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
+       /** Accumulate (add) @a len frames @a src starting at @a src_offset into self starting at @a dst_offset */
        void accumulate_from (const Sample* src, framecnt_t len, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
                assert(_capacity > 0);
                assert(len <= _capacity);
@@ -103,12 +117,12 @@ public:
                const Sample* const src_raw = src + src_offset;
 
                mix_buffers_no_gain(dst_raw, src_raw, len);
-               
+
                _silent = false;
                _written = true;
        }
 
-       /** Acumulate (add) @a len frames @a src starting at @a src_offset into self starting at @dst_offset
+       /** Accumulate (add) @a len frames @a src starting at @a src_offset into self starting at @dst_offset
         * scaling by @a gain_coeff */
        void accumulate_with_gain_from (const AudioBuffer& src, framecnt_t len, gain_t gain_coeff, framecnt_t dst_offset = 0, framecnt_t src_offset = 0) {
 
@@ -162,6 +176,10 @@ public:
                _written = true;
        }
 
+       /** apply a fixed gain factor to the audio buffer
+        * @param gain gain factor
+        * @param len number of frames to amplify
+        */
        void apply_gain (gain_t gain, framecnt_t len) {
                apply_gain_to_buffer (_data, len, gain);
        }
@@ -173,7 +191,6 @@ public:
        void set_data (Sample* data, size_t size) {
                assert(!_owns_data); // prevent leaks
                _capacity = size;
-               _size = size;
                _data = data;
                _silent = false;
                _written = false;
@@ -185,8 +202,6 @@ public:
         */
        void resize (size_t nframes);
 
-       bool empty() const { return _size == 0; }
-
        const Sample* data (framecnt_t offset = 0) const {
                assert(offset <= _capacity);
                return _data + offset;
@@ -198,9 +213,20 @@ public:
                return _data + offset;
        }
 
-       bool check_silence (pframes_t, bool, pframes_t&) const;
+       /** check buffer for silence
+        * @param nframes  number of frames to check
+        * @param n first non zero sample (if any)
+        * @return true if all samples are zero
+        */
+       bool check_silence (pframes_t nframes, pframes_t& n) const;
 
-       void prepare () { _written = false; _silent = false; }
+       void prepare () {
+               if (!_owns_data) {
+                       _data = 0;
+               }
+               _written = false;
+               _silent = false;
+       }
        bool written() const { return _written; }
        void set_written(bool w) { _written = w; }