From 1b9ad6ec7b2f86c2cf140190002b65a99613bc65 Mon Sep 17 00:00:00 2001
From: brian-ch <brian-ch@b956fd51-792f-4845-bead-9b4dfca2ff2c>
Date: Sun, 12 Apr 2015 18:50:58 +0000
Subject: Small correction in the ffmpeg 2.5 headers (almost only comments)
git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@3115 b956fd51-792f-4845-bead-9b4dfca2ff2c
---
src/lib/ffmpeg-2.5/avcodec.pas | 54 ++++++++++++++++++++++++-----------------
src/lib/ffmpeg-2.5/avformat.pas | 2 +-
2 files changed, 33 insertions(+), 23 deletions(-)
(limited to 'src/lib')
diff --git a/src/lib/ffmpeg-2.5/avcodec.pas b/src/lib/ffmpeg-2.5/avcodec.pas
index d52bd8f0..8425fb91 100644
--- a/src/lib/ffmpeg-2.5/avcodec.pas
+++ b/src/lib/ffmpeg-2.5/avcodec.pas
@@ -4756,19 +4756,25 @@ function avcodec_decode_audio3(avctx: PAVCodecContext; samples: PSmallint;
* Decode the audio frame of size avpkt->size from avpkt->data into frame.
*
* Some decoders may support multiple frames in a single AVPacket. Such
- * decoders would then just decode the first frame. In this case,
- * avcodec_decode_audio4 has to be called again with an AVPacket containing
- * the remaining data in order to decode the second frame, etc...
- * Even if no frames are returned, the packet needs to be fed to the decoder
- * with remaining data until it is completely consumed or an error occurs.
+ * decoders would then just decode the first frame and the return value would be
+ * less than the packet size. In this case, avcodec_decode_audio4 has to be
+ * called again with an AVPacket containing the remaining data in order to
+ * decode the second frame, etc... Even if no frames are returned, the packet
+ * needs to be fed to the decoder with remaining data until it is completely
+ * consumed or an error occurs.
+ *
+ * Some decoders (those marked with CODEC_CAP_DELAY) have a delay between input
+ * and output. This means that for some packets they will not immediately
+ * produce decoded output and need to be flushed at the end of decoding to get
+ * all the decoded data. Flushing is done by calling this function with packets
+ * with avpkt->data set to NULL and avpkt->size set to 0 until it stops
+ * returning samples. It is safe to flush even those decoders that are not
+ * marked with CODEC_CAP_DELAY, then no samples will be returned.
*
* @warning The input buffer, avpkt->data must be FF_INPUT_BUFFER_PADDING_SIZE
* larger than the actual read bytes because some optimized bitstream
* readers read 32 or 64 bits at once and could read over the end.
*
- * @note You might have to align the input buffer. The alignment requirements
- * depend on the CPU and the decoder.
- *
* @param avctx the codec context
* @param[out] frame The AVFrame in which to store decoded audio samples.
* The decoder will allocate a buffer for the decoded frame by
@@ -4780,10 +4786,13 @@ function avcodec_decode_audio3(avctx: PAVCodecContext; samples: PSmallint;
* to the frame if av_frame_is_writable() returns 1.
* When AVCodecContext.refcounted_frames is set to 0, the returned
* reference belongs to the decoder and is valid only until the
- * next call to this function or until closing the decoder.
- * The caller may not write to it.
+ * next call to this function or until closing or flushing the
+ * decoder. The caller may not write to it.
* @param[out] got_frame_ptr Zero if no frame could be decoded, otherwise it is
- * non-zero.
+ * non-zero. Note that this field being set to zero
+ * does not mean that an error has occurred. For
+ * decoders with CODEC_CAP_DELAY set, no given decode
+ * call is guaranteed to produce a frame.
* @param[in] avpkt The input AVPacket containing the input buffer.
* At least avpkt->data and avpkt->size should be set. Some
* decoders might also require additional fields to be set.
@@ -4807,13 +4816,6 @@ function avcodec_decode_audio4(avctx: PAVCodecContext; frame: PAVFrame;
* @warning The end of the input buffer buf should be set to 0 to ensure that
* no overreading happens for damaged MPEG streams.
*
- * @note You might have to align the input buffer avpkt->data.
- * The alignment requirements depend on the CPU: on some CPUs it isn't
- * necessary at all, on others it won't work at all if not aligned and on others
- * it will work but it will have an impact on performance.
- *
- * In practice, avpkt->data should have 4 byte alignment at minimum.
- *
* @note Codecs which have the CODEC_CAP_DELAY capability set have a delay
* between input and output, these need to be fed with avpkt->data=NULL,
* avpkt->size=0 at the end to return the remaining frames.
@@ -4830,10 +4832,10 @@ function avcodec_decode_audio4(avctx: PAVCodecContext; frame: PAVFrame;
* to the frame if av_frame_is_writable() returns 1.
* When AVCodecContext.refcounted_frames is set to 0, the returned
* reference belongs to the decoder and is valid only until the
- * next call to this function or until closing the decoder. The
- * caller may not write to it.
+ * next call to this function or until closing or flushing the
+ * decoder. The caller may not write to it.
*
- * @param[in] avpkt The input AVpacket containing the input buffer.
+ * @param[in] avpkt The input AVPacket containing the input buffer.
* You can create such packet with av_init_packet() and by then setting
* data and size, some decoders might in addition need other fields like
* flags&AV_PKT_FLAG_KEY. All decoders are designed to use the least
@@ -4847,7 +4849,8 @@ function avcodec_decode_video2(avctx: PAVCodecContext; picture: PAVFrame;
avpkt: {const} PAVPacket): cint;
cdecl; external av__codec;
-(* Decode a subtitle message.
+(*
+ * Decode a subtitle message.
* Return a negative value on error, otherwise return the number of bytes used.
* If no subtitle could be decompressed, got_sub_ptr is zero.
* Otherwise, the subtitle is stored in *sub.
@@ -5032,6 +5035,13 @@ type
*)
picture_structure: TAVPictureStructure;
+ (**
+ * Picture number incremented in presentation or output order.
+ * This field may be reinitialized at the first picture of a new sequence.
+ *
+ * For example, this corresponds to H.264 PicOrderCnt.
+ *)
+ output_picture_number: cint;
end; {AVCodecParserContext}
TAVCodecParser = record
diff --git a/src/lib/ffmpeg-2.5/avformat.pas b/src/lib/ffmpeg-2.5/avformat.pas
index 89177a5e..ce2effce 100644
--- a/src/lib/ffmpeg-2.5/avformat.pas
+++ b/src/lib/ffmpeg-2.5/avformat.pas
@@ -1734,7 +1734,7 @@ type
*)
format_whitelist: PAnsiChar;
- (*****************************************************************
+ (*****************************************************************
* All fields below this line are not part of the public API. They
* may not be used outside of libavformat and can be changed and
* removed at will.
--
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