1 files changed, 416 insertions, 0 deletions

diff --git a/media/ffvpx/libavutil/buffer.c b/media/ffvpx/libavutil/buffer.c
new file mode 100644
index 0000000000..e4562a79b1
--- /dev/null
+++ b/media/ffvpx/libavutil/buffer.c
@@ -0,0 +1,416 @@
+/*
+ * 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 <stdatomic.h>
+#include <stdint.h>
+#include <string.h>
+
+#include "avassert.h"
+#include "buffer_internal.h"
+#include "common.h"
+#include "mem.h"
+#include "thread.h"
+
+static AVBufferRef *buffer_create(AVBuffer *buf, uint8_t *data, size_t size,
+                                  void (*free)(void *opaque, uint8_t *data),
+                                  void *opaque, int flags)
+{
+    AVBufferRef *ref = NULL;
+
+    buf->data     = data;
+    buf->size     = size;
+    buf->free     = free ? free : av_buffer_default_free;
+    buf->opaque   = opaque;
+
+    atomic_init(&buf->refcount, 1);
+
+    buf->flags = flags;
+
+    ref = av_mallocz(sizeof(*ref));
+    if (!ref)
+        return NULL;
+
+    ref->buffer = buf;
+    ref->data   = data;
+    ref->size   = size;
+
+    return ref;
+}
+
+AVBufferRef *av_buffer_create(uint8_t *data, size_t size,
+                              void (*free)(void *opaque, uint8_t *data),
+                              void *opaque, int flags)
+{
+    AVBufferRef *ret;
+    AVBuffer *buf = av_mallocz(sizeof(*buf));
+    if (!buf)
+        return NULL;
+
+    ret = buffer_create(buf, data, size, free, opaque, flags);
+    if (!ret) {
+        av_free(buf);
+        return NULL;
+    }
+    return ret;
+}
+
+void av_buffer_default_free(void *opaque, uint8_t *data)
+{
+    av_free(data);
+}
+
+AVBufferRef *av_buffer_alloc(size_t 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(size_t size)
+{
+    AVBufferRef *ret = av_buffer_alloc(size);
+    if (!ret)
+        return NULL;
+
+    memset(ret->data, 0, size);
+    return ret;
+}
+
+AVBufferRef *av_buffer_ref(const AVBufferRef *buf)
+{
+    AVBufferRef *ret = av_mallocz(sizeof(*ret));
+
+    if (!ret)
+        return NULL;
+
+    *ret = *buf;
+
+    atomic_fetch_add_explicit(&buf->buffer->refcount, 1, memory_order_relaxed);
+
+    return ret;
+}
+
+static void buffer_replace(AVBufferRef **dst, AVBufferRef **src)
+{
+    AVBuffer *b;
+
+    b = (*dst)->buffer;
+
+    if (src) {
+        **dst = **src;
+        av_freep(src);
+    } else
+        av_freep(dst);
+
+    if (atomic_fetch_sub_explicit(&b->refcount, 1, memory_order_acq_rel) == 1) {
+        /* b->free below might already free the structure containing *b,
+         * so we have to read the flag now to avoid use-after-free. */
+        int free_avbuffer = !(b->flags_internal & BUFFER_FLAG_NO_FREE);
+        b->free(b->opaque, b->data);
+        if (free_avbuffer)
+            av_free(b);
+    }
+}
+
+void av_buffer_unref(AVBufferRef **buf)
+{
+    if (!buf || !*buf)
+        return;
+
+    buffer_replace(buf, NULL);
+}
+
+int av_buffer_is_writable(const AVBufferRef *buf)
+{
+    if (buf->buffer->flags & AV_BUFFER_FLAG_READONLY)
+        return 0;
+
+    return atomic_load(&buf->buffer->refcount) == 1;
+}
+
+void *av_buffer_get_opaque(const AVBufferRef *buf)
+{
+    return buf->buffer->opaque;
+}
+
+int av_buffer_get_ref_count(const AVBufferRef *buf)
+{
+    return atomic_load(&buf->buffer->refcount);
+}
+
+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);
+
+    buffer_replace(pbuf, &newbuf);
+
+    return 0;
+}
+
+int av_buffer_realloc(AVBufferRef **pbuf, size_t size)
+{
+    AVBufferRef *buf = *pbuf;
+    uint8_t *tmp;
+    int ret;
+
+    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_internal |= BUFFER_FLAG_REALLOCATABLE;
+        *pbuf = buf;
+
+        return 0;
+    } else if (buf->size == size)
+        return 0;
+
+    if (!(buf->buffer->flags_internal & BUFFER_FLAG_REALLOCATABLE) ||
+        !av_buffer_is_writable(buf) || buf->data != buf->buffer->data) {
+        /* cannot realloc, allocate a new reallocable buffer and copy data */
+        AVBufferRef *new = NULL;
+
+        ret = av_buffer_realloc(&new, size);
+        if (ret < 0)
+            return ret;
+
+        memcpy(new->data, buf->data, FFMIN(size, buf->size));
+
+        buffer_replace(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;
+}
+
+int av_buffer_replace(AVBufferRef **pdst, const AVBufferRef *src)
+{
+    AVBufferRef *dst = *pdst;
+    AVBufferRef *tmp;
+
+    if (!src) {
+        av_buffer_unref(pdst);
+        return 0;
+    }
+
+    if (dst && dst->buffer == src->buffer) {
+        /* make sure the data pointers match */
+        dst->data = src->data;
+        dst->size = src->size;
+        return 0;
+    }
+
+    tmp = av_buffer_ref(src);
+    if (!tmp)
+        return AVERROR(ENOMEM);
+
+    av_buffer_unref(pdst);
+    *pdst = tmp;
+    return 0;
+}
+
+AVBufferPool *av_buffer_pool_init2(size_t size, void *opaque,
+                                   AVBufferRef* (*alloc)(void *opaque, size_t size),
+                                   void (*pool_free)(void *opaque))
+{
+    AVBufferPool *pool = av_mallocz(sizeof(*pool));
+    if (!pool)
+        return NULL;
+
+    ff_mutex_init(&pool->mutex, NULL);
+
+    pool->size      = size;
+    pool->opaque    = opaque;
+    pool->alloc2    = alloc;
+    pool->alloc     = av_buffer_alloc; // fallback
+    pool->pool_free = pool_free;
+
+    atomic_init(&pool->refcount, 1);
+
+    return pool;
+}
+
+AVBufferPool *av_buffer_pool_init(size_t size, AVBufferRef* (*alloc)(size_t size))
+{
+    AVBufferPool *pool = av_mallocz(sizeof(*pool));
+    if (!pool)
+        return NULL;
+
+    ff_mutex_init(&pool->mutex, NULL);
+
+    pool->size     = size;
+    pool->alloc    = alloc ? alloc : av_buffer_alloc;
+
+    atomic_init(&pool->refcount, 1);
+
+    return pool;
+}
+
+static void buffer_pool_flush(AVBufferPool *pool)
+{
+    while (pool->pool) {
+        BufferPoolEntry *buf = pool->pool;
+        pool->pool = buf->next;
+
+        buf->free(buf->opaque, buf->data);
+        av_freep(&buf);
+    }
+}
+
+/*
+ * This function gets called when the pool has been uninited and
+ * all the buffers returned to it.
+ */
+static void buffer_pool_free(AVBufferPool *pool)
+{
+    buffer_pool_flush(pool);
+    ff_mutex_destroy(&pool->mutex);
+
+    if (pool->pool_free)
+        pool->pool_free(pool->opaque);
+
+    av_freep(&pool);
+}
+
+void av_buffer_pool_uninit(AVBufferPool **ppool)
+{
+    AVBufferPool *pool;
+
+    if (!ppool || !*ppool)
+        return;
+    pool   = *ppool;
+    *ppool = NULL;
+
+    ff_mutex_lock(&pool->mutex);
+    buffer_pool_flush(pool);
+    ff_mutex_unlock(&pool->mutex);
+
+    if (atomic_fetch_sub_explicit(&pool->refcount, 1, memory_order_acq_rel) == 1)
+        buffer_pool_free(pool);
+}
+
+static void pool_release_buffer(void *opaque, uint8_t *data)
+{
+    BufferPoolEntry *buf = opaque;
+    AVBufferPool *pool = buf->pool;
+
+    ff_mutex_lock(&pool->mutex);
+    buf->next = pool->pool;
+    pool->pool = buf;
+    ff_mutex_unlock(&pool->mutex);
+
+    if (atomic_fetch_sub_explicit(&pool->refcount, 1, memory_order_acq_rel) == 1)
+        buffer_pool_free(pool);
+}
+
+/* allocate a new buffer and override its free() callback so that
+ * it is returned to the pool on free */
+static AVBufferRef *pool_alloc_buffer(AVBufferPool *pool)
+{
+    BufferPoolEntry *buf;
+    AVBufferRef     *ret;
+
+    av_assert0(pool->alloc || pool->alloc2);
+
+    ret = pool->alloc2 ? pool->alloc2(pool->opaque, pool->size) :
+                         pool->alloc(pool->size);
+    if (!ret)
+        return NULL;
+
+    buf = av_mallocz(sizeof(*buf));
+    if (!buf) {
+        av_buffer_unref(&ret);
+        return NULL;
+    }
+
+    buf->data   = ret->buffer->data;
+    buf->opaque = ret->buffer->opaque;
+    buf->free   = ret->buffer->free;
+    buf->pool   = pool;
+
+    ret->buffer->opaque = buf;
+    ret->buffer->free   = pool_release_buffer;
+
+    return ret;
+}
+
+AVBufferRef *av_buffer_pool_get(AVBufferPool *pool)
+{
+    AVBufferRef *ret;
+    BufferPoolEntry *buf;
+
+    ff_mutex_lock(&pool->mutex);
+    buf = pool->pool;
+    if (buf) {
+        memset(&buf->buffer, 0, sizeof(buf->buffer));
+        ret = buffer_create(&buf->buffer, buf->data, pool->size,
+                            pool_release_buffer, buf, 0);
+        if (ret) {
+            pool->pool = buf->next;
+            buf->next = NULL;
+            buf->buffer.flags_internal |= BUFFER_FLAG_NO_FREE;
+        }
+    } else {
+        ret = pool_alloc_buffer(pool);
+    }
+    ff_mutex_unlock(&pool->mutex);
+
+    if (ret)
+        atomic_fetch_add_explicit(&pool->refcount, 1, memory_order_relaxed);
+
+    return ret;
+}
+
+void *av_buffer_pool_buffer_get_opaque(const AVBufferRef *ref)
+{
+    BufferPoolEntry *buf = ref->buffer->opaque;
+    av_assert0(buf);
+    return buf->opaque;
+}