/*
- * This file is part of Libav.
+ * This file is part of FFmpeg.
*
- * Libav is free software; you can redistribute it and/or
+ * 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.
*
- * Libav is distributed in the hope that it will be useful,
+ * 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 Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stddef.h>
#include <stdint.h>
+#include "libavutil/buffer.h"
+
#include "avcodec.h"
+/*
+ * This defines a framework for converting between a coded bitstream
+ * and structures defining all individual syntax elements found in
+ * such a stream.
+ *
+ * Conversion in both directions is possible. Given a coded bitstream
+ * (any meaningful fragment), it can be parsed and decomposed into
+ * syntax elements stored in a set of codec-specific structures.
+ * Similarly, given a set of those same codec-specific structures the
+ * syntax elements can be serialised and combined to create a coded
+ * bitstream.
+ */
+
struct CodedBitstreamType;
+/**
+ * The codec-specific type of a bitstream unit.
+ *
+ * H.264 / AVC: nal_unit_type
+ * H.265 / HEVC: nal_unit_type
+ * MPEG-2: start code value (without prefix)
+ */
+typedef uint32_t CodedBitstreamUnitType;
+
/**
* Coded bitstream unit structure.
*
- * A bitstream unit the the smallest element of a bitstream which
+ * A bitstream unit the smallest element of a bitstream which
* is meaningful on its own. For example, an H.264 NAL unit.
*
* See the codec-specific header for the meaning of this for any
/**
* Codec-specific type of this unit.
*/
- uint32_t type;
+ CodedBitstreamUnitType type;
/**
- * Pointer to the bitstream form of this unit.
+ * Pointer to the directly-parsable bitstream form of this unit.
*
* May be NULL if the unit currently only exists in decomposed form.
*/
* This supports non-byte-aligned bitstreams.
*/
size_t data_bit_padding;
+ /**
+ * If data is reference counted, a reference to the buffer containing
+ * data. Null if data is not reference counted.
+ */
+ AVBufferRef *data_ref;
/**
* Pointer to the decomposed form of this unit.
*/
void *content;
/**
- * Whether the content was supplied externally.
- *
- * If so, it should not be freed when freeing the unit.
+ * If content is reference counted, a reference to the buffer containing
+ * content. Null if content is not reference counted.
*/
- int content_external;
+ AVBufferRef *content_ref;
} CodedBitstreamUnit;
/**
* The number of bits which should be ignored in the final byte.
*/
size_t data_bit_padding;
+ /**
+ * If data is reference counted, a reference to the buffer containing
+ * data. Null if data is not reference counted.
+ */
+ AVBufferRef *data_ref;
/**
* Number of units in this fragment.
*
- * This may be zero if the fragment only exists in bistream form
+ * This may be zero if the fragment only exists in bitstream form
* and has not been decomposed.
*/
int nb_units;
* Types not in this list will be available in bitstream form only.
* If NULL, all supported types will be decomposed.
*/
- uint32_t *decompose_unit_types;
+ CodedBitstreamUnitType *decompose_unit_types;
/**
* Length of the decompose_unit_types array.
*/
- int nb_decompose_unit_types;
+ int nb_decompose_unit_types;
/**
* Enable trace output during read/write operations.
} CodedBitstreamContext;
+/**
+ * Table of all supported codec IDs.
+ *
+ * Terminated by AV_CODEC_ID_NONE.
+ */
+extern const enum AVCodecID ff_cbs_all_codec_ids[];
+
+
/**
* Create and initialise a new context for the given codec.
*/
/**
* Read the data bitstream from a packet into a fragment, then
* split into units and decompose.
+ *
+ * This also updates the internal state of the coded bitstream context
+ * with any persistent data from the fragment which may be required to
+ * read following fragments (e.g. parameter sets).
*/
int ff_cbs_read_packet(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag,
/**
* Read a bitstream from a memory region into a fragment, then
* split into units and decompose.
+ *
+ * This also updates the internal state of the coded bitstream context
+ * with any persistent data from the fragment which may be required to
+ * read following fragments (e.g. parameter sets).
*/
int ff_cbs_read(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag,
* data buffer. When modifying the content of decomposed units, this
* can be used to regenerate the bitstream form of units or the whole
* fragment so that it can be extracted for other use.
+ *
+ * This also updates the internal state of the coded bitstream context
+ * with any persistent data from the fragment which may be required to
+ * write following fragments (e.g. parameter sets).
*/
int ff_cbs_write_fragment_data(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag);
/**
* Write the bitstream of a fragment to the extradata in codec parameters.
+ *
+ * This replaces any existing extradata in the structure.
*/
int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
AVCodecParameters *par,
CodedBitstreamFragment *frag);
+/**
+ * Allocate a new internal content buffer of the given size in the unit.
+ *
+ * The content will be zeroed.
+ */
+int ff_cbs_alloc_unit_content(CodedBitstreamContext *ctx,
+ CodedBitstreamUnit *unit,
+ size_t size,
+ void (*free)(void *unit, uint8_t *content));
+
+/**
+ * Allocate a new internal data buffer of the given size in the unit.
+ *
+ * The data buffer will have input padding.
+ */
+int ff_cbs_alloc_unit_data(CodedBitstreamContext *ctx,
+ CodedBitstreamUnit *unit,
+ size_t size);
+
/**
* Insert a new unit into a fragment with the given content.
*
- * The content structure continues to be owned by the caller, and
- * will not be freed when the unit is.
+ * The content structure continues to be owned by the caller if
+ * content_buf is not supplied.
*/
int ff_cbs_insert_unit_content(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag,
- int position, uint32_t type,
- void *content);
+ int position,
+ CodedBitstreamUnitType type,
+ void *content,
+ AVBufferRef *content_buf);
/**
* Insert a new unit into a fragment with the given data bitstream.
*
- * The data buffer will be owned by the unit after this operation.
+ * If data_buf is not supplied then data must have been allocated with
+ * av_malloc() and will become owned by the unit after this call.
*/
int ff_cbs_insert_unit_data(CodedBitstreamContext *ctx,
CodedBitstreamFragment *frag,
- int position, uint32_t type,
- uint8_t *data, size_t data_size);
+ int position,
+ CodedBitstreamUnitType type,
+ uint8_t *data, size_t data_size,
+ AVBufferRef *data_buf);
/**
* Delete a unit from a fragment and free all memory it uses.
projects / ffmpeg / blobdiff