libavcodec/decode.h

   1 /*
   2  * generic decoding-related code
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef AVCODEC_DECODE_H
  22 #define AVCODEC_DECODE_H
  23
  24 #include "libavutil/buffer.h"
  25 #include "libavutil/frame.h"
  26 #include "libavutil/hwcontext.h"
  27
  28 #include "avcodec.h"
  29
  30 /**
  31  * This struct stores per-frame lavc-internal data and is attached to it via
  32  * opaque_ref.
  33  */
  34 typedef struct FrameDecodeData {
  35     /**
  36      * The original user-set opaque_ref.
  37      */
  38     AVBufferRef *user_opaque_ref;
  39
  40     /**
  41      * The callback to perform some delayed processing on the frame right
  42      * before it is returned to the caller.
  43      *
  44      * @note This code is called at some unspecified point after the frame is
  45      * returned from the decoder's decode/receive_frame call. Therefore it cannot rely
  46      * on AVCodecContext being in any specific state, so it does not get to
  47      * access AVCodecContext directly at all. All the state it needs must be
  48      * stored in the post_process_opaque object.
  49      */
  50     int (*post_process)(void *logctx, AVFrame *frame);
  51     void *post_process_opaque;
  52     void (*post_process_opaque_free)(void *opaque);
  53
  54     /**
  55      * Per-frame private data for hwaccels.
  56      */
  57     void *hwaccel_priv;
  58     void (*hwaccel_priv_free)(void *priv);
  59 } FrameDecodeData;
  60
  61 /**
  62  * Called by decoders to get the next packet for decoding.
  63  *
  64  * @param pkt An empty packet to be filled with data.
  65  * @return 0 if a new reference has been successfully written to pkt
  66  *         AVERROR(EAGAIN) if no data is currently available
  67  *         AVERROR_EOF if and end of stream has been reached, so no more data
  68  *                     will be available
  69  */
  70 int ff_decode_get_packet(AVCodecContext *avctx, AVPacket *pkt);
  71
  72 int ff_decode_bsfs_init(AVCodecContext *avctx);
  73
  74 void ff_decode_bsfs_uninit(AVCodecContext *avctx);
  75
  76 /**
  77  * Make sure avctx.hw_frames_ctx is set. If it's not set, the function will
  78  * try to allocate it from hw_device_ctx. If that is not possible, an error
  79  * message is printed, and an error code is returned.
  80  */
  81 int ff_decode_get_hw_frames_ctx(AVCodecContext *avctx,
  82                                 enum AVHWDeviceType dev_type);
  83
  84 #endif /* AVCODEC_DECODE_H */