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<a href="buffer_8h.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment"> * This file is part of FFmpeg.</span>
<a name="l00003"></a>00003 <span class="comment"> *</span>
<a name="l00004"></a>00004 <span class="comment"> * FFmpeg is free software; you can redistribute it and/or</span>
<a name="l00005"></a>00005 <span class="comment"> * modify it under the terms of the GNU Lesser General Public</span>
<a name="l00006"></a>00006 <span class="comment"> * License as published by the Free Software Foundation; either</span>
<a name="l00007"></a>00007 <span class="comment"> * version 2.1 of the License, or (at your option) any later version.</span>
<a name="l00008"></a>00008 <span class="comment"> *</span>
<a name="l00009"></a>00009 <span class="comment"> * FFmpeg is distributed in the hope that it will be useful,</span>
<a name="l00010"></a>00010 <span class="comment"> * but WITHOUT ANY WARRANTY; without even the implied warranty of</span>
<a name="l00011"></a>00011 <span class="comment"> * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU</span>
<a name="l00012"></a>00012 <span class="comment"> * Lesser General Public License for more details.</span>
<a name="l00013"></a>00013 <span class="comment"> *</span>
<a name="l00014"></a>00014 <span class="comment"> * You should have received a copy of the GNU Lesser General Public</span>
<a name="l00015"></a>00015 <span class="comment"> * License along with FFmpeg; if not, write to the Free Software</span>
<a name="l00016"></a>00016 <span class="comment"> * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA</span>
<a name="l00017"></a>00017 <span class="comment"> */</span>
<a name="l00018"></a>00018 <span class="comment"></span>
<a name="l00019"></a>00019 <span class="comment">/**</span>
<a name="l00020"></a>00020 <span class="comment"> * @file</span>
<a name="l00021"></a>00021 <span class="comment"> * @ingroup lavu_buffer</span>
<a name="l00022"></a>00022 <span class="comment"> * refcounted data buffer API</span>
<a name="l00023"></a>00023 <span class="comment"> */</span>
<a name="l00024"></a>00024
<a name="l00025"></a>00025 <span class="preprocessor">#ifndef AVUTIL_BUFFER_H</span>
<a name="l00026"></a>00026 <span class="preprocessor"></span><span class="preprocessor">#define AVUTIL_BUFFER_H</span>
<a name="l00027"></a>00027 <span class="preprocessor"></span>
<a name="l00028"></a>00028 <span class="preprocessor">#include <stdint.h></span>
<a name="l00029"></a>00029 <span class="comment"></span>
<a name="l00030"></a>00030 <span class="comment">/**</span>
<a name="l00031"></a>00031 <span class="comment"> * @defgroup lavu_buffer AVBuffer</span>
<a name="l00032"></a>00032 <span class="comment"> * @ingroup lavu_data</span>
<a name="l00033"></a>00033 <span class="comment"> *</span>
<a name="l00034"></a>00034 <span class="comment"> * @{</span>
<a name="l00035"></a>00035 <span class="comment"> * AVBuffer is an API for reference-counted data buffers.</span>
<a name="l00036"></a>00036 <span class="comment"> *</span>
<a name="l00037"></a>00037 <span class="comment"> * There are two core objects in this API -- AVBuffer and AVBufferRef. AVBuffer</span>
<a name="l00038"></a>00038 <span class="comment"> * represents the data buffer itself; it is opaque and not meant to be accessed</span>
<a name="l00039"></a>00039 <span class="comment"> * by the caller directly, but only through AVBufferRef. However, the caller may</span>
<a name="l00040"></a>00040 <span class="comment"> * e.g. compare two AVBuffer pointers to check whether two different references</span>
<a name="l00041"></a>00041 <span class="comment"> * are describing the same data buffer. AVBufferRef represents a single</span>
<a name="l00042"></a>00042 <span class="comment"> * reference to an AVBuffer and it is the object that may be manipulated by the</span>
<a name="l00043"></a>00043 <span class="comment"> * caller directly.</span>
<a name="l00044"></a>00044 <span class="comment"> *</span>
<a name="l00045"></a>00045 <span class="comment"> * There are two functions provided for creating a new AVBuffer with a single</span>
<a name="l00046"></a>00046 <span class="comment"> * reference -- av_buffer_alloc() to just allocate a new buffer, and</span>
<a name="l00047"></a>00047 <span class="comment"> * av_buffer_create() to wrap an existing array in an AVBuffer. From an existing</span>
<a name="l00048"></a>00048 <span class="comment"> * reference, additional references may be created with av_buffer_ref().</span>
<a name="l00049"></a>00049 <span class="comment"> * Use av_buffer_unref() to free a reference (this will automatically free the</span>
<a name="l00050"></a>00050 <span class="comment"> * data once all the references are freed).</span>
<a name="l00051"></a>00051 <span class="comment"> *</span>
<a name="l00052"></a>00052 <span class="comment"> * The convention throughout this API and the rest of FFmpeg is such that the</span>
<a name="l00053"></a>00053 <span class="comment"> * buffer is considered writable if there exists only one reference to it (and</span>
<a name="l00054"></a>00054 <span class="comment"> * it has not been marked as read-only). The av_buffer_is_writable() function is</span>
<a name="l00055"></a>00055 <span class="comment"> * provided to check whether this is true and av_buffer_make_writable() will</span>
<a name="l00056"></a>00056 <span class="comment"> * automatically create a new writable buffer when necessary.</span>
<a name="l00057"></a>00057 <span class="comment"> * Of course nothing prevents the calling code from violating this convention,</span>
<a name="l00058"></a>00058 <span class="comment"> * however that is safe only when all the existing references are under its</span>
<a name="l00059"></a>00059 <span class="comment"> * control.</span>
<a name="l00060"></a>00060 <span class="comment"> *</span>
<a name="l00061"></a>00061 <span class="comment"> * @note Referencing and unreferencing the buffers is thread-safe and thus</span>
<a name="l00062"></a>00062 <span class="comment"> * may be done from multiple threads simultaneously without any need for</span>
<a name="l00063"></a>00063 <span class="comment"> * additional locking.</span>
<a name="l00064"></a>00064 <span class="comment"> *</span>
<a name="l00065"></a>00065 <span class="comment"> * @note Two different references to the same buffer can point to different</span>
<a name="l00066"></a>00066 <span class="comment"> * parts of the buffer (i.e. their AVBufferRef.data will not be equal).</span>
<a name="l00067"></a>00067 <span class="comment"> */</span>
<a name="l00068"></a>00068 <span class="comment"></span>
<a name="l00069"></a>00069 <span class="comment">/**</span>
<a name="l00070"></a>00070 <span class="comment"> * A reference counted buffer type. It is opaque and is meant to be used through</span>
<a name="l00071"></a>00071 <span class="comment"> * references (AVBufferRef).</span>
<a name="l00072"></a>00072 <span class="comment"> */</span>
<a name="l00073"></a><a class="code" href="group__lavu__buffer.html#ga501d49df442180d584f255aa97b2549d">00073</a> <span class="keyword">typedef</span> <span class="keyword">struct </span><a class="code" href="group__lavu__buffer.html#ga501d49df442180d584f255aa97b2549d" title="A reference counted buffer type.">AVBuffer</a> <a class="code" href="group__lavu__buffer.html#ga501d49df442180d584f255aa97b2549d" title="A reference counted buffer type.">AVBuffer</a>;
<a name="l00074"></a>00074 <span class="comment"></span>
<a name="l00075"></a>00075 <span class="comment">/**</span>
<a name="l00076"></a>00076 <span class="comment"> * A reference to a data buffer.</span>
<a name="l00077"></a>00077 <span class="comment"> *</span>
<a name="l00078"></a>00078 <span class="comment"> * The size of this struct is not a part of the public ABI and it is not meant</span>
<a name="l00079"></a>00079 <span class="comment"> * to be allocated directly.</span>
<a name="l00080"></a>00080 <span class="comment"> */</span>
<a name="l00081"></a><a class="code" href="structAVBufferRef.html">00081</a> <span class="keyword">typedef</span> <span class="keyword">struct </span><a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> {
<a name="l00082"></a><a class="code" href="structAVBufferRef.html#a3c692274c56720d7903bbd35bcaec3a2">00082</a> <a class="code" href="group__lavu__buffer.html#ga501d49df442180d584f255aa97b2549d" title="A reference counted buffer type.">AVBuffer</a> *<a class="code" href="structAVBufferRef.html#a3c692274c56720d7903bbd35bcaec3a2">buffer</a>;
<a name="l00083"></a>00083 <span class="comment"></span>
<a name="l00084"></a>00084 <span class="comment"> /**</span>
<a name="l00085"></a>00085 <span class="comment"> * The data buffer. It is considered writable if and only if</span>
<a name="l00086"></a>00086 <span class="comment"> * this is the only reference to the buffer, in which case</span>
<a name="l00087"></a>00087 <span class="comment"> * av_buffer_is_writable() returns 1.</span>
<a name="l00088"></a>00088 <span class="comment"> */</span>
<a name="l00089"></a><a class="code" href="structAVBufferRef.html#acb8452e99cd75074b93800b532c6ea4b">00089</a> uint8_t *<a class="code" href="structAVBufferRef.html#acb8452e99cd75074b93800b532c6ea4b" title="The data buffer.">data</a>;<span class="comment"></span>
<a name="l00090"></a>00090 <span class="comment"> /**</span>
<a name="l00091"></a>00091 <span class="comment"> * Size of data in bytes.</span>
<a name="l00092"></a>00092 <span class="comment"> */</span>
<a name="l00093"></a><a class="code" href="structAVBufferRef.html#a55f17b82a5af97259a5e8a3fd9647a08">00093</a> <span class="keywordtype">int</span> <a class="code" href="structAVBufferRef.html#a55f17b82a5af97259a5e8a3fd9647a08" title="Size of data in bytes.">size</a>;
<a name="l00094"></a>00094 } <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a>;
<a name="l00095"></a>00095 <span class="comment"></span>
<a name="l00096"></a>00096 <span class="comment">/**</span>
<a name="l00097"></a>00097 <span class="comment"> * Allocate an AVBuffer of the given size using av_malloc().</span>
<a name="l00098"></a>00098 <span class="comment"> *</span>
<a name="l00099"></a>00099 <span class="comment"> * @return an AVBufferRef of given size or NULL when out of memory</span>
<a name="l00100"></a>00100 <span class="comment"> */</span>
<a name="l00101"></a>00101 <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *<a class="code" href="group__lavu__buffer.html#ga5ae84ac902283dea1a660ede06c1cdac" title="Allocate an AVBuffer of the given size using av_malloc().">av_buffer_alloc</a>(<span class="keywordtype">int</span> size);
<a name="l00102"></a>00102 <span class="comment"></span>
<a name="l00103"></a>00103 <span class="comment">/**</span>
<a name="l00104"></a>00104 <span class="comment"> * Same as av_buffer_alloc(), except the returned buffer will be initialized</span>
<a name="l00105"></a>00105 <span class="comment"> * to zero.</span>
<a name="l00106"></a>00106 <span class="comment"> */</span>
<a name="l00107"></a>00107 <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *<a class="code" href="group__lavu__buffer.html#ga27f37cc004f768b00442b6cb08091686" title="Same as av_buffer_alloc(), except the returned buffer will be initialized to zero.">av_buffer_allocz</a>(<span class="keywordtype">int</span> size);
<a name="l00108"></a>00108 <span class="comment"></span>
<a name="l00109"></a>00109 <span class="comment">/**</span>
<a name="l00110"></a>00110 <span class="comment"> * Always treat the buffer as read-only, even when it has only one</span>
<a name="l00111"></a>00111 <span class="comment"> * reference.</span>
<a name="l00112"></a>00112 <span class="comment"> */</span>
<a name="l00113"></a><a class="code" href="group__lavu__buffer.html#gaa818f8f1011d69acc50c1f29cb85e576">00113</a> <span class="preprocessor">#define AV_BUFFER_FLAG_READONLY (1 << 0)</span>
<a name="l00114"></a>00114 <span class="preprocessor"></span><span class="comment"></span>
<a name="l00115"></a>00115 <span class="comment">/**</span>
<a name="l00116"></a>00116 <span class="comment"> * Create an AVBuffer from an existing array.</span>
<a name="l00117"></a>00117 <span class="comment"> *</span>
<a name="l00118"></a>00118 <span class="comment"> * If this function is successful, data is owned by the AVBuffer. The caller may</span>
<a name="l00119"></a>00119 <span class="comment"> * only access data through the returned AVBufferRef and references derived from</span>
<a name="l00120"></a>00120 <span class="comment"> * it.</span>
<a name="l00121"></a>00121 <span class="comment"> * If this function fails, data is left untouched.</span>
<a name="l00122"></a>00122 <span class="comment"> * @param data data array</span>
<a name="l00123"></a>00123 <span class="comment"> * @param size size of data in bytes</span>
<a name="l00124"></a>00124 <span class="comment"> * @param free a callback for freeing this buffer's data</span>
<a name="l00125"></a>00125 <span class="comment"> * @param opaque parameter to be got for processing or passed to free</span>
<a name="l00126"></a>00126 <span class="comment"> * @param flags a combination of AV_BUFFER_FLAG_*</span>
<a name="l00127"></a>00127 <span class="comment"> *</span>
<a name="l00128"></a>00128 <span class="comment"> * @return an AVBufferRef referring to data on success, NULL on failure.</span>
<a name="l00129"></a>00129 <span class="comment"> */</span>
<a name="l00130"></a>00130 <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *<a class="code" href="group__lavu__buffer.html#ga3e7f4c92db85ccba0b2a16dd0069842a" title="Create an AVBuffer from an existing array.">av_buffer_create</a>(uint8_t *data, <span class="keywordtype">int</span> size,
<a name="l00131"></a>00131 <span class="keywordtype">void</span> (*free)(<span class="keywordtype">void</span> *opaque, uint8_t *data),
<a name="l00132"></a>00132 <span class="keywordtype">void</span> *opaque, <span class="keywordtype">int</span> flags);
<a name="l00133"></a>00133 <span class="comment"></span>
<a name="l00134"></a>00134 <span class="comment">/**</span>
<a name="l00135"></a>00135 <span class="comment"> * Default free callback, which calls av_free() on the buffer data.</span>
<a name="l00136"></a>00136 <span class="comment"> * This function is meant to be passed to av_buffer_create(), not called</span>
<a name="l00137"></a>00137 <span class="comment"> * directly.</span>
<a name="l00138"></a>00138 <span class="comment"> */</span>
<a name="l00139"></a>00139 <span class="keywordtype">void</span> <a class="code" href="group__lavu__buffer.html#ga37d620e8cfc9f2f3261c2b4c5d4adfe0" title="Default free callback, which calls av_free() on the buffer data.">av_buffer_default_free</a>(<span class="keywordtype">void</span> *opaque, uint8_t *data);
<a name="l00140"></a>00140 <span class="comment"></span>
<a name="l00141"></a>00141 <span class="comment">/**</span>
<a name="l00142"></a>00142 <span class="comment"> * Create a new reference to an AVBuffer.</span>
<a name="l00143"></a>00143 <span class="comment"> *</span>
<a name="l00144"></a>00144 <span class="comment"> * @return a new AVBufferRef referring to the same AVBuffer as buf or NULL on</span>
<a name="l00145"></a>00145 <span class="comment"> * failure.</span>
<a name="l00146"></a>00146 <span class="comment"> */</span>
<a name="l00147"></a>00147 <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *<a class="code" href="group__lavu__buffer.html#gaa40ce7d3ede946a89d03323bbd7268c1" title="Create a new reference to an AVBuffer.">av_buffer_ref</a>(<a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *buf);
<a name="l00148"></a>00148 <span class="comment"></span>
<a name="l00149"></a>00149 <span class="comment">/**</span>
<a name="l00150"></a>00150 <span class="comment"> * Free a given reference and automatically free the buffer if there are no more</span>
<a name="l00151"></a>00151 <span class="comment"> * references to it.</span>
<a name="l00152"></a>00152 <span class="comment"> *</span>
<a name="l00153"></a>00153 <span class="comment"> * @param buf the reference to be freed. The pointer is set to NULL on return.</span>
<a name="l00154"></a>00154 <span class="comment"> */</span>
<a name="l00155"></a>00155 <span class="keywordtype">void</span> <a class="code" href="group__lavu__buffer.html#ga135e9e929b5033bb8f68322497b2effc" title="Free a given reference and automatically free the buffer if there are no more references to it...">av_buffer_unref</a>(<a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> **buf);
<a name="l00156"></a>00156 <span class="comment"></span>
<a name="l00157"></a>00157 <span class="comment">/**</span>
<a name="l00158"></a>00158 <span class="comment"> * @return 1 if the caller may write to the data referred to by buf (which is</span>
<a name="l00159"></a>00159 <span class="comment"> * true if and only if buf is the only reference to the underlying AVBuffer).</span>
<a name="l00160"></a>00160 <span class="comment"> * Return 0 otherwise.</span>
<a name="l00161"></a>00161 <span class="comment"> * A positive answer is valid until av_buffer_ref() is called on buf.</span>
<a name="l00162"></a>00162 <span class="comment"> */</span>
<a name="l00163"></a>00163 <span class="keywordtype">int</span> <a class="code" href="group__lavu__buffer.html#ga060be34ace567ae378fd0a786e847053">av_buffer_is_writable</a>(<span class="keyword">const</span> <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *buf);
<a name="l00164"></a>00164 <span class="comment"></span>
<a name="l00165"></a>00165 <span class="comment">/**</span>
<a name="l00166"></a>00166 <span class="comment"> * @return the opaque parameter set by av_buffer_create.</span>
<a name="l00167"></a>00167 <span class="comment"> */</span>
<a name="l00168"></a>00168 <span class="keywordtype">void</span> *<a class="code" href="group__lavu__buffer.html#gac1c38f469fc9933885cfffafd8cbf0d6">av_buffer_get_opaque</a>(<span class="keyword">const</span> <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *buf);
<a name="l00169"></a>00169
<a name="l00170"></a>00170 <span class="keywordtype">int</span> <a class="code" href="group__lavu__buffer.html#ga7b16c3976dc555f71d0843bbd023dfcd">av_buffer_get_ref_count</a>(<span class="keyword">const</span> <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *buf);
<a name="l00171"></a>00171 <span class="comment"></span>
<a name="l00172"></a>00172 <span class="comment">/**</span>
<a name="l00173"></a>00173 <span class="comment"> * Create a writable reference from a given buffer reference, avoiding data copy</span>
<a name="l00174"></a>00174 <span class="comment"> * if possible.</span>
<a name="l00175"></a>00175 <span class="comment"> *</span>
<a name="l00176"></a>00176 <span class="comment"> * @param buf buffer reference to make writable. On success, buf is either left</span>
<a name="l00177"></a>00177 <span class="comment"> * untouched, or it is unreferenced and a new writable AVBufferRef is</span>
<a name="l00178"></a>00178 <span class="comment"> * written in its place. On failure, buf is left untouched.</span>
<a name="l00179"></a>00179 <span class="comment"> * @return 0 on success, a negative AVERROR on failure.</span>
<a name="l00180"></a>00180 <span class="comment"> */</span>
<a name="l00181"></a>00181 <span class="keywordtype">int</span> <a class="code" href="group__lavu__buffer.html#ga9c2a1be1b7bb80eec8613fdb62a19074" title="Create a writable reference from a given buffer reference, avoiding data copy if possible.">av_buffer_make_writable</a>(<a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> **buf);
<a name="l00182"></a>00182 <span class="comment"></span>
<a name="l00183"></a>00183 <span class="comment">/**</span>
<a name="l00184"></a>00184 <span class="comment"> * Reallocate a given buffer.</span>
<a name="l00185"></a>00185 <span class="comment"> *</span>
<a name="l00186"></a>00186 <span class="comment"> * @param buf a buffer reference to reallocate. On success, buf will be</span>
<a name="l00187"></a>00187 <span class="comment"> * unreferenced and a new reference with the required size will be</span>
<a name="l00188"></a>00188 <span class="comment"> * written in its place. On failure buf will be left untouched. *buf</span>
<a name="l00189"></a>00189 <span class="comment"> * may be NULL, then a new buffer is allocated.</span>
<a name="l00190"></a>00190 <span class="comment"> * @param size required new buffer size.</span>
<a name="l00191"></a>00191 <span class="comment"> * @return 0 on success, a negative AVERROR on failure.</span>
<a name="l00192"></a>00192 <span class="comment"> *</span>
<a name="l00193"></a>00193 <span class="comment"> * @note the buffer is actually reallocated with av_realloc() only if it was</span>
<a name="l00194"></a>00194 <span class="comment"> * initially allocated through av_buffer_realloc(NULL) and there is only one</span>
<a name="l00195"></a>00195 <span class="comment"> * reference to it (i.e. the one passed to this function). In all other cases</span>
<a name="l00196"></a>00196 <span class="comment"> * a new buffer is allocated and the data is copied.</span>
<a name="l00197"></a>00197 <span class="comment"> */</span>
<a name="l00198"></a>00198 <span class="keywordtype">int</span> <a class="code" href="group__lavu__buffer.html#gac7c228f9ed54e246dcd270503bed7291" title="Reallocate a given buffer.">av_buffer_realloc</a>(<a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> **buf, <span class="keywordtype">int</span> size);
<a name="l00199"></a>00199 <span class="comment"></span>
<a name="l00200"></a>00200 <span class="comment">/**</span>
<a name="l00201"></a>00201 <span class="comment"> * @}</span>
<a name="l00202"></a>00202 <span class="comment"> */</span>
<a name="l00203"></a>00203 <span class="comment"></span>
<a name="l00204"></a>00204 <span class="comment">/**</span>
<a name="l00205"></a>00205 <span class="comment"> * @defgroup lavu_bufferpool AVBufferPool</span>
<a name="l00206"></a>00206 <span class="comment"> * @ingroup lavu_data</span>
<a name="l00207"></a>00207 <span class="comment"> *</span>
<a name="l00208"></a>00208 <span class="comment"> * @{</span>
<a name="l00209"></a>00209 <span class="comment"> * AVBufferPool is an API for a lock-free thread-safe pool of AVBuffers.</span>
<a name="l00210"></a>00210 <span class="comment"> *</span>
<a name="l00211"></a>00211 <span class="comment"> * Frequently allocating and freeing large buffers may be slow. AVBufferPool is</span>
<a name="l00212"></a>00212 <span class="comment"> * meant to solve this in cases when the caller needs a set of buffers of the</span>
<a name="l00213"></a>00213 <span class="comment"> * same size (the most obvious use case being buffers for raw video or audio</span>
<a name="l00214"></a>00214 <span class="comment"> * frames).</span>
<a name="l00215"></a>00215 <span class="comment"> *</span>
<a name="l00216"></a>00216 <span class="comment"> * At the beginning, the user must call av_buffer_pool_init() to create the</span>
<a name="l00217"></a>00217 <span class="comment"> * buffer pool. Then whenever a buffer is needed, call av_buffer_pool_get() to</span>
<a name="l00218"></a>00218 <span class="comment"> * get a reference to a new buffer, similar to av_buffer_alloc(). This new</span>
<a name="l00219"></a>00219 <span class="comment"> * reference works in all aspects the same way as the one created by</span>
<a name="l00220"></a>00220 <span class="comment"> * av_buffer_alloc(). However, when the last reference to this buffer is</span>
<a name="l00221"></a>00221 <span class="comment"> * unreferenced, it is returned to the pool instead of being freed and will be</span>
<a name="l00222"></a>00222 <span class="comment"> * reused for subsequent av_buffer_pool_get() calls.</span>
<a name="l00223"></a>00223 <span class="comment"> *</span>
<a name="l00224"></a>00224 <span class="comment"> * When the caller is done with the pool and no longer needs to allocate any new</span>
<a name="l00225"></a>00225 <span class="comment"> * buffers, av_buffer_pool_uninit() must be called to mark the pool as freeable.</span>
<a name="l00226"></a>00226 <span class="comment"> * Once all the buffers are released, it will automatically be freed.</span>
<a name="l00227"></a>00227 <span class="comment"> *</span>
<a name="l00228"></a>00228 <span class="comment"> * Allocating and releasing buffers with this API is thread-safe as long as</span>
<a name="l00229"></a>00229 <span class="comment"> * either the default alloc callback is used, or the user-supplied one is</span>
<a name="l00230"></a>00230 <span class="comment"> * thread-safe.</span>
<a name="l00231"></a>00231 <span class="comment"> */</span>
<a name="l00232"></a>00232 <span class="comment"></span>
<a name="l00233"></a>00233 <span class="comment">/**</span>
<a name="l00234"></a>00234 <span class="comment"> * The buffer pool. This structure is opaque and not meant to be accessed</span>
<a name="l00235"></a>00235 <span class="comment"> * directly. It is allocated with av_buffer_pool_init() and freed with</span>
<a name="l00236"></a>00236 <span class="comment"> * av_buffer_pool_uninit().</span>
<a name="l00237"></a>00237 <span class="comment"> */</span>
<a name="l00238"></a><a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6">00238</a> <span class="keyword">typedef</span> <span class="keyword">struct </span><a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6" title="The buffer pool.">AVBufferPool</a> <a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6" title="The buffer pool.">AVBufferPool</a>;
<a name="l00239"></a>00239 <span class="comment"></span>
<a name="l00240"></a>00240 <span class="comment">/**</span>
<a name="l00241"></a>00241 <span class="comment"> * Allocate and initialize a buffer pool.</span>
<a name="l00242"></a>00242 <span class="comment"> *</span>
<a name="l00243"></a>00243 <span class="comment"> * @param size size of each buffer in this pool</span>
<a name="l00244"></a>00244 <span class="comment"> * @param alloc a function that will be used to allocate new buffers when the</span>
<a name="l00245"></a>00245 <span class="comment"> * pool is empty. May be NULL, then the default allocator will be used</span>
<a name="l00246"></a>00246 <span class="comment"> * (av_buffer_alloc()).</span>
<a name="l00247"></a>00247 <span class="comment"> * @return newly created buffer pool on success, NULL on error.</span>
<a name="l00248"></a>00248 <span class="comment"> */</span>
<a name="l00249"></a>00249 <a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6" title="The buffer pool.">AVBufferPool</a> *<a class="code" href="group__lavu__bufferpool.html#ga26af9b07c08bc7fd2cfc62767e490b93" title="Allocate and initialize a buffer pool.">av_buffer_pool_init</a>(<span class="keywordtype">int</span> size, <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a>* (*alloc)(<span class="keywordtype">int</span> size));
<a name="l00250"></a>00250 <span class="comment"></span>
<a name="l00251"></a>00251 <span class="comment">/**</span>
<a name="l00252"></a>00252 <span class="comment"> * Mark the pool as being available for freeing. It will actually be freed only</span>
<a name="l00253"></a>00253 <span class="comment"> * once all the allocated buffers associated with the pool are released. Thus it</span>
<a name="l00254"></a>00254 <span class="comment"> * is safe to call this function while some of the allocated buffers are still</span>
<a name="l00255"></a>00255 <span class="comment"> * in use.</span>
<a name="l00256"></a>00256 <span class="comment"> *</span>
<a name="l00257"></a>00257 <span class="comment"> * @param pool pointer to the pool to be freed. It will be set to NULL.</span>
<a name="l00258"></a>00258 <span class="comment"> * @see av_buffer_pool_can_uninit()</span>
<a name="l00259"></a>00259 <span class="comment"> */</span>
<a name="l00260"></a>00260 <span class="keywordtype">void</span> <a class="code" href="group__lavu__bufferpool.html#ga7b76781c5944b3bb59b2e3b1a8994e4a" title="Mark the pool as being available for freeing.">av_buffer_pool_uninit</a>(<a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6" title="The buffer pool.">AVBufferPool</a> **pool);
<a name="l00261"></a>00261 <span class="comment"></span>
<a name="l00262"></a>00262 <span class="comment">/**</span>
<a name="l00263"></a>00263 <span class="comment"> * Allocate a new AVBuffer, reusing an old buffer from the pool when available.</span>
<a name="l00264"></a>00264 <span class="comment"> * This function may be called simultaneously from multiple threads.</span>
<a name="l00265"></a>00265 <span class="comment"> *</span>
<a name="l00266"></a>00266 <span class="comment"> * @return a reference to the new buffer on success, NULL on error.</span>
<a name="l00267"></a>00267 <span class="comment"> */</span>
<a name="l00268"></a>00268 <a class="code" href="structAVBufferRef.html" title="A reference to a data buffer.">AVBufferRef</a> *<a class="code" href="group__lavu__bufferpool.html#ga2c745ecb4001452423e775b06b20fb7c" title="Allocate a new AVBuffer, reusing an old buffer from the pool when available.">av_buffer_pool_get</a>(<a class="code" href="group__lavu__bufferpool.html#ga13bc8038952b61bae4d591f30c7421f6" title="The buffer pool.">AVBufferPool</a> *pool);
<a name="l00269"></a>00269 <span class="comment"></span>
<a name="l00270"></a>00270 <span class="comment">/**</span>
<a name="l00271"></a>00271 <span class="comment"> * @}</span>
<a name="l00272"></a>00272 <span class="comment"> */</span>
<a name="l00273"></a>00273
<a name="l00274"></a>00274 <span class="preprocessor">#endif </span><span class="comment">/* AVUTIL_BUFFER_H */</span>
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