* qatar/master:
Drop git- prefix from version labels
Use the contents of RELEASE as version fallback instead of 'UNKNOWN'
path64/open64: filter out unsupported flags
Add Release Notes
sipr: Drop unused DSPContext
sipr: include string.h for mem*()
sipr: Use memmove() to copy overlapped buffers.
h264: drop some ugly casts
Conflicts:
version.sh
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The list type was changed to int64_t to be able to hold
channel layouts.
avfilter_make_format_list() still takes a int32_t array and converts
it to int64_t. A new function, avfilter_make_format64_list, that
takes int64_t arrays has been added.
* qatar/master:
lavc: add opt_find to AVCodecContext class.
h264: Complexify frame num gap shortening code
intreadwrite.h: fix AV_RL32/AV_RB32 signedness.
Fix decoding of mpegts streams with h264 video that does *NOT* have b frames
Add minor bumps and APIChanges entries for lavf private options.
ffmpeg: deprecate -vc and -tvstd
ffmpeg: use new avformat_open_* API.
ffserver: use new avformat_open_* API.
ffprobe: use new avformat_open_* API.
ffplay: use new avformat_open_* API.
cmdutils: add opt_default2().
dict: add AV_DICT_APPEND flag.
lavf: add avformat_write_header() as a replacement for av_write_header().
Deprecate av_open_input_* and remove their uses.
lavf: add avformat_open_input() as a replacement for av_open_input_*
AVOptions: add av_opt_find() as a replacement for av_find_opt.
AVOptions: add av_opt_set_dict() mapping a dictionary struct to a context.
ffmpeg: don't abuse a global for passing frame size from input to output
ffmpeg: don't abuse a global for passing pixel format from input to output
ffmpeg: initialise encoders earlier.
Conflicts:
cmdutils.c
doc/APIchanges
ffmpeg.c
ffplay.c
ffprobe.c
libavcodec/h264.c
libavformat/avformat.h
libavformat/utils.c
libavformat/version.h
libavutil/avutil.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
bitstream: Properly promote av_reverse values before shifting.
libavutil/swscale: YUV444P10/YUV444P9 support.
H.264: Fix high bit depth explicit biweight
h264: Fix 10-bit H.264 x86 chroma v loopfilter asm.
Replace DEBUG_SEEK/DEBUG_SI + av_log combinations by av_dlog.
Update copyright year for ac3enc_opts_template.c.
adts: Adjust frame size mask to follow the specification.
movenc: Add RTP muxer/hinter options
movenc: Pass the RTP AVFormatContext to the SDP generation
rtspenc: Add RTP muxer options
rtspenc: Add an AVClass for setting muxer specific options
rtpenc_chain: Pass the rtpflags options through to the chained muxer
rtpenc: Declare the rtp flags private AVOptions in rtpenc.h
sdp: Reindent after the previous commit
rtpenc: MP4A-LATM payload support
avoptions: Add an av_opt_flag_is_set function for inspecting flag fields
sdp: Allow passing an AVFormatContext to the SDP generation
mov: Fix wrong timestamp generation for fragmented movies that have time offset caused by the first edit list entry.
mpeg12: more advanced ffmpeg mpeg2 aspect guessing code.
swscale: split YUYV output out of yuv2packed[12X]_c().
Conflicts:
doc/APIchanges
libavcodec/Makefile
libavcodec/h264dsp_template.c
libavcodec/mpeg12.c
libavformat/aacdec.c
libavformat/avidec.c
libavformat/internal.h
libavformat/movenc.c
libavformat/rtpenc.c
libavformat/rtpenc_latm.c
libavformat/sdp.c
libavformat/version.h
libavutil/avutil.h
libavutil/pixfmt.h
libswscale/swscale.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
crypto: Use av_freep instead of av_free
lavf: don't try to free private options if priv_data is NULL.
swscale: fix types of assembly arguments.
swscale: move two macros that are only used once into caller.
swscale: remove unused function.
options: Add missing braces around struct initializer.
mov: Remove leftover crufty debug statement with references to a local file.
dvbsubdec: Fix compilation of debug code.
Remove all uses of now deprecated metadata functions.
Move metadata API from lavf to lavu.
Conflicts:
doc/APIchanges
libavformat/aiffdec.c
libavformat/asfdec.c
libavformat/avformat.h
libavformat/avidec.c
libavformat/cafdec.c
libavformat/matroskaenc.c
libavformat/mov.c
libavformat/mp3enc.c
libavformat/wtv.c
libavutil/avutil.h
libavutil/internal.h
libswscale/swscale.c
libswscale/x86/swscale_template.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Deprecate av_get_bits_per_sample_fmt(), which was a misnamed function.
For the moment we don't have sample formats with a non-integer number
of bytes, in that case we may need to create a new
av_get_bits_per_sample() function. In the meanwhile we prefer to adopt
this variant, since avoids divisions by 8 all over the place.
Remove AVFilterBufferRefAudioProps.size, and use nb_samples in
avfilter_get_audio_buffer() and avfilter_default_get_audio_buffer() in
place of size.
This is required as the size in the audio buffer may be aligned, so it
may not contain a well defined number of samples.
The new layout is consistent with that of the av_image_() API, and
simplifies understanding and copy operations, it also preserves
alignment information which was lost with the previous layout.
This breaks API/ABI, but since the function was never referenced in
the code (and it isn't unlikely already used by someone) then this
should not be a problem.
* qatar/master:
Remove some unused scripts from tools/.
Add x86 assembly for some 10-bit H.264 intra predict functions.
v4l2: do not force NTSC as standard
Skip tableprint.h during 'make checkheaders'.
Remove unnecessary LIBAVFORMAT_BUILD #ifdef.
Drop explicit filenames from @file Doxygen tags.
Skip generated table headers during 'make checkheaders'.
lavf,lavc: free avoptions in a generic way.
AVOptions: add av_opt_free convenience function.
tableprint: Restore mistakenly deleted common.h #include for FF_ARRAY_ELEMS.
tiff: print log in case of unknown / unsupported tag.
tiff: fix linesize for mono-white/black formats.
Fix build of eval-test program
configure: Document --enable-vaapi
ac3enc: extract all exponents for the frame at once
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The new flags parameter allows to specify if the video ref to add
should overwrite the cache, if the flag is not set vsrc_buffer will
complain and abort; otherwise it will clean the already cached video
ref before to overwrite it, thus avoiding a leak.
* qatar/master: (27 commits)
ac3enc: fix LOCAL_ALIGNED usage in count_mantissa_bits()
ac3dsp: do not use the ff_* prefix when referencing ff_ac3_bap_bits.
ac3dsp: fix loop condition in ac3_update_bap_counts_c()
ARM: unbreak build
ac3enc: modify mantissa bit counting to keep bap counts for all values of bap instead of just 0 to 4.
ac3enc: split mantissa bit counting into a separate function.
ac3enc: store per-block/channel bap pointers by reference block in a 2D array rather than in the AC3Block struct.
get_bits: add av_unused tag to cache variable
sws: replace all long with int.
ARM: aacdec: fix constraints on inline asm
ARM: remove unnecessary volatile from inline asm
ARM: add "cc" clobbers to inline asm where needed
ARM: improve FASTDIV asm
ac3enc: use LOCAL_ALIGNED macro
APIchanges: fill in git hash for av_get_pix_fmt_name (0420bd7).
lavu: add av_get_pix_fmt_name() convenience function
cmdutils: remove OPT_FUNC2
swscale: fix crash in bilinear scaling.
vpxenc: add VP8E_SET_STATIC_THRESHOLD mapping
webm: support stereo videos in matroska/webm muxer
...
Conflicts:
Changelog
cmdutils.c
cmdutils.h
doc/APIchanges
doc/muxers.texi
ffmpeg.c
ffplay.c
libavcodec/ac3enc.c
libavcodec/ac3enc_float.c
libavcodec/avcodec.h
libavcodec/get_bits.h
libavcodec/libvpxenc.c
libavcodec/version.h
libavdevice/libdc1394.c
libavformat/matroskaenc.c
libavutil/avutil.h
libswscale/rgb2rgb.c
libswscale/swscale.c
libswscale/swscale_template.c
libswscale/x86/swscale_template.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Remove reference to the mplayerhq.hu rsync command, and replace it
with a reference to the make fate-rsync command.
rsync needs still to be enabled on mplayerhq.hu, and it is currently
not working. Also the fate-rsync Makefile target can be easily updated
without the need to keep the docs in synch.
* qatar/master: (31 commits)
ARM: add ARMv6 optimised av_clip_uintp2
ARM: remove volatile from asm statements in libavutil/intmath
ARM: fix av_clipl_int32_arm()
v4l: include avdevice.h
ffserver: move close_connection() call to avoid a temporary string and copy.
lavf: initialize demuxer private options.
AVOptions: set string default values.
lavdevice: mark v4l for removal on next major bump.
swscale: fix compile on ppc.
swscale: fix compile on x86-32.
build: Remove generated .version file on distclean.
configure: Add -D_GNU_SOURCE to CPPFLAGS on OS/2.
doc: Drop hint at --enable-memalign-hack for MinGW, it is now autodetected.
ffplay: Remove disabled code.
Mark parameterless function declarations as 'void'.
swscale: use av_clip_uint8() in yuv2yuv1_c().
swscale: remove VOF/VOFW.
swscale: split chroma buffers into separate U/V planes.
swscale: replace formatConvBuffer[VOF] by allocated array.
rgb2rgb: remove duplicate mmx/mmx2/3dnow/sse2 functions.
...
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master: (32 commits)
doc: create separate section for audio encoders
swscale: Remove orphaned, commented-out function declaration.
swscale: Eliminate rgb24toyv12_c() duplication.
Remove h263_msmpeg4 from MpegEncContext.
APIchanges: Fill in git hash for fps_probe_size (30315a8)
avformat: Add fpsprobesize as an AVOption.
avoptions: Return explicitly NAN or {0,0} if the option isn't found
rtmp: Reindent
rtmp: Don't try to do av_malloc(0)
tty: replace AVFormatParameters.sample_rate abuse with a private option.
Fix end time of last chapter in compute_chapters_end
ffmpeg: get rid of useless AVInputStream.nb_streams.
ffmpeg: simplify managing input files and streams
ffmpeg: purge redundant AVInputStream.index.
lavf: deprecate AVFormatParameters.channel.
libdc1394: add a private option for channel.
dv1394: add a private option for channel.
v4l2: reindent.
v4l2: add a private option for channel.
lavf: deprecate AVFormatParameters.standard.
...
Conflicts:
doc/APIchanges
doc/encoders.texi
ffmpeg.c
libavdevice/alsa-audio.h
libavformat/version.h
libavutil/opt.c
libswscale/rgb2rgb.h
libswscale/rgb2rgb_template.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Having a separate section for audio encoders simplifies navigation
and is slightly more consistent with the rest of the manual.
Signed-off-by: Diego Biurrun <diego@biurrun.de>
* qatar/master: (22 commits)
configure: enable memalign_hack automatically when needed
swscale: unbreak the build on non-x86 systems.
swscale: remove if(bitexact) branch from functions.
swscale: remove if(canMMX2BeUsed) conditional.
swscale: remove swScale_{c,MMX,MMX2} duplication.
swscale: use emms_c().
Move emms_c() from libavcodec to libavutil.
tiff: set palette in the context when specified in TIFF_PAL tag
rtsp: use strtoul to parse rtptime and seq values.
pgssubdec: fix incorrect colors.
dvdsubdec: fix incorrect colors.
ape: Allow demuxing of files with metadata tags.
swscale: remove dead macro WRITEBGR24OLD.
swscale: remove AMD3DNOW "optimizations".
swscale: remove duplicate code in ppc/ subdirectory.
swscale: remove duplicated x86/ functions.
swscale: force --enable-runtime-cpudetect and remove SWS_CPU_CAPS_*.
vsrc_buffer.h: add file doxy
vsrc_buffer: tweak error message in init()
msmpeg4: reindent.
...
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Channel coupling is an optional AC-3 feature that increases quality by
combining high frequency information from multiple channels into a
single channel. The per-channel high frequency information is sent with
less accuracy in both the frequency and time domains. This allows more
bits to be used for lower frequencies while preserving enough
information to reconstruct the high frequencies.
The new function accepts a slightly more intuitive order of paramters,
and returns an error code, thus allowing applications to report a
meaningful error message.
Make Audio Encoders a separate chapter, and decrese the contained
sections level by one.
Improve rendering, and improve consistency with the other parts of the
manual.
The new function is a wrapper around
av_vsrc_buffer_add_video_buffer_ref(), and allows to simplify the act
of pushing AVFrame data to the source buffer.
* qatar/master:
APIchanges: fill in date and commit for request_sample_fmt
Add floating-point sample format support to the ac3, eac3, dca, aac, and vorbis decoders.
Add support for request_sample_format in ffmpeg and ffplay.
Add APIchanges entry for request_sample_fmt.
Add request_sample_fmt field to AVCodecContext.
Add float_interleave() to FmtConvertContext with x86-optimized versions.
Remove unused make variable SEEK_REFFILE
fate: remove redundant aref and vref references
fate: remove do_ffmpeg_nocheck function
fate: do not collect -benchmark output
mpegaudiodec: remove decode_end() function
fate: run aref and vref as regular tests
mpegaudio: sanitise compute_antialias_* names
mpeg12: add slice-threading checks to slice-threading initializers.
h264: copy pixel_shift between slice threading contexts.
mdec: enable frame-level multithreading.
mdec.c: fix overread.
Conflicts:
libavcodec/aacdec.c
libavcodec/ac3dec.c
libavcodec/avcodec.h
libavcodec/dca.c
libavcodec/h264.c
libavcodec/mdec.c
libavcodec/mpeg12.c
libavcodec/options.c
libavcodec/version.h
libavcodec/vorbisdec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Adding _POSIX_C_SOURCE to CPPFLAGS globally produces all sorts of problems
since it causes certain system functions to be hidden on some (BSD) systems.
The solution is to only add the flag on systems that really require it, i.e.
glibc-based ones.
This change makes BSD systems compile out-of-the-box without the need for
adding specific flags manually. It also allows dropping a number of flags
set manually on a file-per-file basis, but were only present to work around
breakage introduced by the presence of _POSIX_C_SOURCE.
Also add _XOPEN_SOURCE to CPPFLAGS for glibc systems. We use XSI extensions
in several places already, so it is preferable to define it globally instead
of littering source files with individual #defines only needed for glibc.
* qatar/master: (32 commits)
10-bit H.264 x86 chroma v loopfilter asm
Port SMPTE S302M audio decoder from FFmbc 0.3. [Copyright headers corrected]
Fix crash of interlaced MPEG2 decoding
h264pred: fix one more aliasing violation.
doc/APIchanges: fill in missing hashes and dates.
flacenc: use proper initializers for AVOption default values.
lavc: deprecate named constants for deprecated antialias_algo.
aac: workaround for compilation on cygwin
swscale: extend YUV422p support to 10bits depth
tiff: add support for inverted FillOrder for uncompressed data
Remove unused softfloat implementation.
h264pred: fix aliasing violations.
rotozoom: Eliminate French variable name.
rotozoom: Check return value of fread().
rotozoom: Return an error value instead of calling exit().
rotozoom: Make init_demo() return int and check for errors on invocation.
rotozoom: Drop silly UINT8 typedef.
rotozoom: Drop some unnecessary parentheses.
rotozoom: K&R coding style cosmetics
rtsp: Only do keepalive using GET_PARAMETER if the server supports it
...
Conflicts:
Changelog
cmdutils.c
doc/APIchanges
doc/general.texi
ffmpeg.c
ffplay.c
libavcodec/h264pred_template.c
libavcodec/resample.c
libavutil/pixfmt.h
libavutil/softfloat.c
libavutil/softfloat.h
tests/rotozoom.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
The softfloat functionality is unused, not installed and incomplete.
On platforms without floating point units, the compiler provides a softfloat
implementation so there is no point in carrying this code around locally.
* qatar/master: (30 commits)
AVOptions: make default_val a union, as proposed in AVOption2.
arm/h264pred: add missing argument type.
h264dsp_mmx: place bracket outside #if/#endif block.
lavf/utils: fix ff_interleave_compare_dts corner case.
fate: add 10-bit H264 tests.
h264: do not print "too many references" warning for intra-only.
Enable decoding of high bit depth h264.
Adds 8-, 9- and 10-bit versions of some of the functions used by the h264 decoder.
Add support for higher QP values in h264.
Add the notion of pixel size in h264 related functions.
Make the h264 loop filter bit depth aware.
Template dsputil_template.c with respect to pixel size, etc.
Template h264idct_template.c with respect to pixel size, etc.
Preparatory patch for high bit depth h264 decoding support.
Move some functions in dsputil.c into a new file dsputil_template.c.
Move the functions in h264idct into a new file h264idct_template.c.
Move the functions in h264pred.c into a new file h264pred_template.c.
Preparatory patch for high bit depth h264 decoding support.
Add pixel formats for 9- and 10-bit yuv420p.
Choose h264 chroma dc dequant function dynamically.
...
Conflicts:
doc/APIchanges
ffmpeg.c
ffplay.c
libavcodec/alpha/dsputil_alpha.c
libavcodec/arm/dsputil_init_arm.c
libavcodec/arm/dsputil_init_armv6.c
libavcodec/arm/dsputil_init_neon.c
libavcodec/arm/dsputil_iwmmxt.c
libavcodec/arm/h264pred_init_arm.c
libavcodec/bfin/dsputil_bfin.c
libavcodec/dsputil.c
libavcodec/h264.c
libavcodec/h264.h
libavcodec/h264_cabac.c
libavcodec/h264_cavlc.c
libavcodec/h264_loopfilter.c
libavcodec/h264_ps.c
libavcodec/h264_refs.c
libavcodec/h264dsp.c
libavcodec/h264idct.c
libavcodec/h264pred.c
libavcodec/mlib/dsputil_mlib.c
libavcodec/options.c
libavcodec/ppc/dsputil_altivec.c
libavcodec/ppc/dsputil_ppc.c
libavcodec/ppc/h264_altivec.c
libavcodec/ps2/dsputil_mmi.c
libavcodec/sh4/dsputil_align.c
libavcodec/sh4/dsputil_sh4.c
libavcodec/sparc/dsputil_vis.c
libavcodec/utils.c
libavcodec/version.h
libavcodec/x86/dsputil_mmx.c
libavformat/options.c
libavformat/utils.c
libavutil/pixfmt.h
libswscale/swscale.c
libswscale/swscale_internal.h
libswscale/swscale_template.c
tests/ref/seek/lavf_avi
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avfilter_copy_frame_props() avoids code duplication and increases
robustness.
The added files libavfilter/avcodec.[ch] are used for containing
utilities useful for gluing togheter libavfilter and libavcodec.
The format is a per-frame property, having it in AVFrame simplify the
operation of extraction of that information, since avoids the need to
access the codec/stream context.
width and height are per-frame properties, setting these values in
AVFrame simplify the operation of extraction of that information,
since avoids the need to check the codec/stream context.
With the following additions:
* support to anti-aliased glyph rendering
* support to UTF-8 text and Unicode chars rendering
* support for RGB packed formats
* fix minor errors and typos in the filter description
* extend/clarify examples in the filter description
Signed-off-by: Anton Khirnov <anton@khirnov.net>
* qatar/master: (23 commits)
doc: Check standalone compilation before submitting new components.
Fix standalone compilation of pipe protocol.
Fix standalone compilation of ac3_fixed encoder.
Fix standalone compilation of binkaudio_dct / binkaudio_rdft decoders.
Fix standalone compilation of IMC decoder.
Fix standalone compilation of WTV demuxer.
Fix standalone compilation of MXPEG decoder.
flashsv: K&R cosmetics
matroskaenc: fix memory leak
vc1: make overlap filter for I-frames bit-exact.
vc1dec: use s->start/end_mb_y instead of passing them as function args.
Revert "VC1: merge idct8x8, coeff adjustments and put_pixels."
Replace strncpy() with av_strlcpy().
indeo3: Eliminate use of long.
get_bits: make cache unsigned to eliminate undefined signed overflow.
asfdec: fix assert failure on invalid files
avfilter: check malloc return values.
Not pulled as reason for reindent is not pulled: mpegvideo: reindent.
nutenc: check malloc return values.
Not pulled due to much simpler solution in ffmpeg *: don't av_malloc(0).
...
Conflicts:
doc/developer.texi
libavcodec/Makefile
libavcodec/get_bits.h
libavcodec/mpegvideo.c
libavformat/Makefile
libavutil/log.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
ALPHA: Replace sized int_fast integer types with plain int/unsigned.
Duplicate DPX image encoder
Duplicate DPX decoder: read sample aspect ratio
Duplciate DPX decoder: add buffer size checks.
ac3enc: clip large coefficient values and negative exponents rather than using av_assert2().
ac3enc: do not store a bandwidth code for each channel.
ac3enc: remove bandwidth reduction as fallback for bit allocation failure.
ac3enc: merge compute_exp_strategy_ch() into compute_exp_strategy()
ac3enc: return error if frame+exponent bits are too large instead of using av_assert2().
ac3enc: differentiate between current block and reference block in bit_alloc()
ac3enc: simplify exponent_init() by calculating exponent_group_tab[] based on exponent group sizes.
ac3enc: simplify stereo rematrixing decision options
Include both URLs: Update URL to fate samples
Conflicts:
Changelog
doc/fate.txt
libavcodec/ac3enc.c
libavcodec/dpxenc.c
libavcodec/version.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Improve consistency with libavcodec.
This breaks libavfilter API/ABI.
The non-sequential 2.1.0 -> 2.4.0 bump is due to the mess previously
done with the lavfi minor number.
The sample aspect ratio is a per-frame property, so it makes sense to
define it in AVFrame rather than in the codec/stream context.
Simplify application-level sample aspect ratio information extraction,
and allow further simplifications.
This is similar to what was done with pkt_pts. This simplifies the
operation of extracting the pos information from the AVPacket, and
allows further simplifications.
* commit '85770f2a2651497861ed938efcd0df3696ff5e45':
AVOptions: make default_val a union, as proposed in AVOption2.
Move ff_dynarray_add to lavu and make it public.
lavf: remove duplicate assignment in avformat_alloc_context.
lavf: use designated initializers for AVClasses.
options: simplify av_find_opt by using av_next_option.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Also deprecate av_get_pict_type_char() in favor of
av_get_picture_type_char().
The new enum and av_get_picture_type_char() are defined in libavutil.
This allows the use in libavfilter without the need to link against
libavcodec.
Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Make the filter accept parametric expressions for the output video
size.
Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
* qatar/master:
Handle unicode file names on windows
rtp: Rename the open/close functions to alloc/free
Lowercase all ff* program names.
Refer to ff* tools by their lowercase names.
NOT Pulled Replace more FFmpeg instances by Libav or ffmpeg.
Replace `` by $() syntax in shell scripts.
patcheck: Allow overiding grep program(s) through environment variables.
NOT Pulled Remove stray libavcore and _g binary references.
vorbis: Rename decoder/encoder files to follow general file naming scheme.
aacenc: Fix whitespace after last commit.
cook: Fix small typo in av_log_ask_for_sample message.
aacenc: Finish 3GPP psymodel analysis for non mid/side cases.
Remove RDFT dependency from AAC decoder.
Add some debug log messages to AAC extradata
Fix mov debug (u)int64_t format strings.
bswap: use native types for av_bwap16().
doc: FLV muxing is supported.
applehttp: Handle AES-128 encrypted streams
Add a protocol handler for AES CBC decryption with PKCS7 padding
doc: Mention that DragonFly BSD requires __BSD_VISIBLE set
Conflicts:
ffplay.c
ffprobe.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
