@@ -14,6 +14,7 @@ HEADERS = adler32.h                                                     \

           blowfish.h                                                    \

           bprint.h                                                      \

           bswap.h                                                       \

+          buffer.h                                                      \

           channel_layout.h                                              \

           common.h                                                      \

           cpu.h                                                         \

@@ -65,6 +66,7 @@ OBJS = adler32.o                                                        \

        base64.o                                                         \

        blowfish.o                                                       \

        bprint.o                                                         \

+       buffer.o                                                         \

        channel_layout.o                                                 \

        cpu.o                                                            \

        crc.o                                                            \

new file mode 100644

@@ -0,0 +1,194 @@

+/*

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * FFmpeg is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+#include <stdint.h>

+#include <string.h>

+

+#include "atomic.h"

+#include "buffer_internal.h"

+#include "common.h"

+#include "mem.h"

+

+AVBufferRef *av_buffer_create(uint8_t *data, int size,

+                              void (*free)(void *opaque, uint8_t *data),

+                              void *opaque, int flags)

+{

+    AVBufferRef *ref = NULL;

+    AVBuffer    *buf = NULL;

+

+    buf = av_mallocz(sizeof(*buf));

+    if (!buf)

+        return NULL;

+

+    buf->data     = data;

+    buf->size     = size;

+    buf->free     = free ? free : av_buffer_default_free;

+    buf->opaque   = opaque;

+    buf->refcount = 1;

+

+    if (flags & AV_BUFFER_FLAG_READONLY)

+        buf->flags |= BUFFER_FLAG_READONLY;

+

+    ref = av_mallocz(sizeof(*ref));

+    if (!ref) {

+        av_freep(&buf);

+        return NULL;

+    }

+

+    ref->buffer = buf;

+    ref->data   = data;

+    ref->size   = size;

+

+    return ref;

+}

+

+void av_buffer_default_free(void *opaque, uint8_t *data)

+{

+    av_free(data);

+}

+

+AVBufferRef *av_buffer_alloc(int size)

+{

+    AVBufferRef *ret = NULL;

+    uint8_t    *data = NULL;

+

+    data = av_malloc(size);

+    if (!data)

+        return NULL;

+

+    ret = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);

+    if (!ret)

+        av_freep(&data);

+

+    return ret;

+}

+

+AVBufferRef *av_buffer_allocz(int size)

+{

+    AVBufferRef *ret = av_buffer_alloc(size);

+    if (!ret)

+        return NULL;

+

+    memset(ret->data, 0, size);

+    return ret;

+}

+

+AVBufferRef *av_buffer_ref(AVBufferRef *buf)

+{

+    AVBufferRef *ret = av_mallocz(sizeof(*ret));

+

+    if (!ret)

+        return NULL;

+

+    *ret = *buf;

+

+    avpriv_atomic_int_add_and_fetch(&buf->buffer->refcount, 1);

+

+    return ret;

+}

+

+void av_buffer_unref(AVBufferRef **buf)

+{

+    AVBuffer *b;

+

+    if (!buf || !*buf)

+        return;

+    b = (*buf)->buffer;

+    av_freep(buf);

+

+    if (!avpriv_atomic_int_add_and_fetch(&b->refcount, -1)) {

+        b->free(b->opaque, b->data);

+        av_freep(&b);

+    }

+}

+

+int av_buffer_is_writable(const AVBufferRef *buf)

+{

+    if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY)

+        return 0;

+

+    return avpriv_atomic_int_add_and_fetch(&buf->buffer->refcount, 0) == 1;

+}

+

+int av_buffer_make_writable(AVBufferRef **pbuf)

+{

+    AVBufferRef *newbuf, *buf = *pbuf;

+

+    if (av_buffer_is_writable(buf))

+        return 0;

+

+    newbuf = av_buffer_alloc(buf->size);

+    if (!newbuf)

+        return AVERROR(ENOMEM);

+

+    memcpy(newbuf->data, buf->data, buf->size);

+    av_buffer_unref(pbuf);

+    *pbuf = newbuf;

+

+    return 0;

+}

+

+int av_buffer_realloc(AVBufferRef **pbuf, int size)

+{

+    AVBufferRef *buf = *pbuf;

+    uint8_t *tmp;

+

+    if (!buf) {

+        /* allocate a new buffer with av_realloc(), so it will be reallocatable

+         * later */

+        uint8_t *data = av_realloc(NULL, size);

+        if (!data)

+            return AVERROR(ENOMEM);

+

+        buf = av_buffer_create(data, size, av_buffer_default_free, NULL, 0);

+        if (!buf) {

+            av_freep(&data);

+            return AVERROR(ENOMEM);

+        }

+

+        buf->buffer->flags |= BUFFER_FLAG_REALLOCATABLE;

+        *pbuf = buf;

+

+        return 0;

+    } else if (buf->size == size)

+        return 0;

+

+    if (!(buf->buffer->flags & BUFFER_FLAG_REALLOCATABLE) ||

+        !av_buffer_is_writable(buf)) {

+        /* cannot realloc, allocate a new reallocable buffer and copy data */

+        AVBufferRef *new = NULL;

+

+        av_buffer_realloc(&new, size);

+        if (!new)

+            return AVERROR(ENOMEM);

+

+        memcpy(new->data, buf->data, FFMIN(size, buf->size));

+

+        av_buffer_unref(pbuf);

+        *pbuf = new;

+        return 0;

+    }

+

+    tmp = av_realloc(buf->buffer->data, size);

+    if (!tmp)

+        return AVERROR(ENOMEM);

+

+    buf->buffer->data = buf->data = tmp;

+    buf->buffer->size = buf->size = size;

+    return 0;

+}

new file mode 100644

@@ -0,0 +1,197 @@

+/*

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * FFmpeg is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+/**

+ * @file

+ * @ingroup lavu_buffer

+ * refcounted data buffer API

+ */

+

+#ifndef AVUTIL_BUFFER_H

+#define AVUTIL_BUFFER_H

+

+#include <stdint.h>

+

+/**

+ * @defgroup lavu_buffer AVBuffer

+ * @ingroup lavu_data

+ *

+ * @{

+ * AVBuffer is an API for reference-counted data buffers.

+ *

+ * There are two core objects in this API -- AVBuffer and AVBufferRef. AVBuffer

+ * represents the data buffer itself; it is opaque and not meant to be accessed

+ * by the caller directly, but only through AVBufferRef. However, the caller may

+ * e.g. compare two AVBuffer pointers to check whether two different references

+ * are describing the same data buffer. AVBufferRef represents a single

+ * reference to an AVBuffer and it is the object that may be manipulated by the

+ * caller directly.

+ *

+ * There are two functions provided for creating a new AVBuffer with a single

+ * reference -- av_buffer_alloc() to just allocate a new buffer, and

+ * av_buffer_create() to wrap an existing array in an AVBuffer. From an existing

+ * reference, additional references may be created with av_buffer_ref().

+ * Use av_buffer_unref() to free a reference (this will automatically free the

+ * data once all the references are freed).

+ *

+ * The convention throughout this API and the rest of FFmpeg is such that the

+ * buffer is considered writable if there exists only one reference to it (and

+ * it has not been marked as read-only). The av_buffer_is_writable() function is

+ * provided to check whether this is true and av_buffer_make_writable() will

+ * automatically create a new writable buffer when necessary.

+ * Of course nothing prevents the calling code from violating this convention,

+ * however that is safe only when all the existing references are under its

+ * control.

+ *

+ * @note Referencing and unreferencing the buffers is thread-safe and thus

+ * may be done from multiple threads simultaneously without any need for

+ * additional locking.

+ *

+ * @note Two different references to the same buffer can point to different

+ * parts of the buffer (i.e. their AVBufferRef.data will not be equal).

+ */

+

+/**

+ * A reference counted buffer type. It is opaque and is meant to be used through

+ * references (AVBufferRef).

+ */

+typedef struct AVBuffer AVBuffer;

+

+/**

+ * A reference to a data buffer.

+ *

+ * The size of this struct is not a part of the public ABI and it is not meant

+ * to be allocated directly.

+ */

+typedef struct AVBufferRef {

+    AVBuffer *buffer;

+

+    /**

+     * The data buffer. It is considered writable if and only if

+     * this is the only reference to the buffer, in which case

+     * av_buffer_is_writable() returns 1.

+     */

+    uint8_t *data;

+    /**

+     * Size of data in bytes.

+     */

+    int      size;

+} AVBufferRef;

+

+/**

+ * Allocate an AVBuffer of the given size using av_malloc().

+ *

+ * @return an AVBufferRef of given size or NULL when out of memory

+ */

+AVBufferRef *av_buffer_alloc(int size);

+

+/**

+ * Same as av_buffer_alloc(), except the returned buffer will be initialized

+ * to zero.

+ */

+AVBufferRef *av_buffer_allocz(int size);

+

+/**

+ * Always treat the buffer as read-only, even when it has only one

+ * reference.

+ */

+#define AV_BUFFER_FLAG_READONLY (1 << 0)

+

+/**

+ * Create an AVBuffer from an existing array.

+ *

+ * If this function is successful, data is owned by the AVBuffer. The caller may

+ * only access data through the returned AVBufferRef and references derived from

+ * it.

+ * If this function fails, data is left untouched.

+ * @param data   data array

+ * @param size   size of data in bytes

+ * @param free   a callback for freeing data

+ * @param opaque parameter to be passed to free

+ * @param flags  a combination of AV_BUFFER_FLAG_*

+ *

+ * @return an AVBufferRef referring to data on success, NULL on failure.

+ */

+AVBufferRef *av_buffer_create(uint8_t *data, int size,

+                              void (*free)(void *opaque, uint8_t *data),

+                              void *opaque, int flags);

+

+/**

+ * Default free callback, which calls av_free() on the buffer data.

+ * This function is meant to be passed to av_buffer_create(), not called

+ * directly.

+ */

+void av_buffer_default_free(void *opaque, uint8_t *data);

+

+/**

+ * Create a new reference to an AVBuffer.

+ *

+ * @return a new AVBufferRef referring to the same AVBuffer as buf or NULL on

+ * failure.

+ */

+AVBufferRef *av_buffer_ref(AVBufferRef *buf);

+

+/**

+ * Free a given reference and automatically free the buffer if there are no more

+ * references to it.

+ *

+ * @param buf the reference to be freed. The pointer is set to NULL on return.

+ */

+void av_buffer_unref(AVBufferRef **buf);

+

+/**

+ * @return 1 if the caller may write to the data referred to by buf (which is

+ * true if and only if buf is the only reference to the underlying AVBuffer).

+ * Return 0 otherwise.

+ * A positive answer is valid until av_buffer_ref() is called on buf.

+ */

+int av_buffer_is_writable(const AVBufferRef *buf);

+

+/**

+ * Create a writable reference from a given buffer reference, avoiding data copy

+ * if possible.

+ *

+ * @param buf buffer reference to make writable. On success, buf is either left

+ *            untouched, or it is unreferenced and a new writable AVBufferRef is

+ *            written in its place. On failure, buf is left untouched.

+ * @return 0 on success, a negative AVERROR on failure.

+ */

+int av_buffer_make_writable(AVBufferRef **buf);

+

+/**

+ * Reallocate a given buffer.

+ *

+ * @param buf  a buffer reference to reallocate. On success, buf will be

+ *             unreferenced and a new reference with the required size will be

+ *             written in its place. On failure buf will be left untouched. *buf

+ *             may be NULL, then a new buffer is allocated.

+ * @param size required new buffer size.

+ * @return 0 on success, a negative AVERROR on failure.

+ *

+ * @note the buffer is actually reallocated with av_realloc() only if it was

+ * initially allocated through av_buffer_realloc(NULL) and there is only one

+ * reference to it (i.e. the one passed to this function). In all other cases

+ * a new buffer is allocated and the data is copied.

+ */

+int av_buffer_realloc(AVBufferRef **buf, int size);

+

+/**

+ * @}

+ */

+

+#endif /* AVUTIL_BUFFER_H */

new file mode 100644

@@ -0,0 +1,60 @@

+/*

+ * This file is part of FFmpeg.

+ *

+ * FFmpeg is free software; you can redistribute it and/or

+ * modify it under the terms of the GNU Lesser General Public

+ * License as published by the Free Software Foundation; either

+ * version 2.1 of the License, or (at your option) any later version.

+ *

+ * FFmpeg is distributed in the hope that it will be useful,

+ * but WITHOUT ANY WARRANTY; without even the implied warranty of

+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

+ * Lesser General Public License for more details.

+ *

+ * You should have received a copy of the GNU Lesser General Public

+ * License along with FFmpeg; if not, write to the Free Software

+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

+ */

+

+#ifndef AVUTIL_BUFFER_INTERNAL_H

+#define AVUTIL_BUFFER_INTERNAL_H

+

+#include <stdint.h>

+

+#include "buffer.h"

+

+/**

+ * The buffer is always treated as read-only.

+ */

+#define BUFFER_FLAG_READONLY      (1 << 0)

+/**

+ * The buffer was av_realloc()ed, so it is reallocatable.

+ */

+#define BUFFER_FLAG_REALLOCATABLE (1 << 1)

+

+struct AVBuffer {

+    uint8_t *data; /**< data described by this buffer */

+    int      size; /**< size of data in bytes */

+

+    /**

+     *  number of existing AVBufferRef instances referring to this buffer

+     */

+    volatile int refcount;

+

+    /**

+     * a callback for freeing the data

+     */

+    void (*free)(void *opaque, uint8_t *data);

+

+    /**

+     * an opaque pointer, to be used by the freeing callback

+     */

+    void *opaque;

+

+    /**

+     * A combination of BUFFER_FLAG_*

+     */

+    int flags;

+};

+

+#endif /* AVUTIL_BUFFER_INTERNAL_H */