Since both the fixed-point and floating-point encoders use the FFTContext,
this no longer needs to be in a separate context. Also, when a short-transform
context is added, the same MDCT window will be used.
* qatar/master: (21 commits)
swscale: Add Doxygen for hyscale_fast/hScale.
fate: enable lavfi-pixmt tests on big endian systems
PPC: swscale: disable altivec functions for unsupported formats
fate: merge identical pixdesc_be/le tests
swscale: Add Doxygen for yuv2planar*/yuv2packed* functions.
build: call texi2pod.pl with full path instead of symlink
build: include sub-makefiles using full path instead of symlinks
swscale: update big endian reference values after dff5a835.
wavpack: skip blocks with no samples
cosmetics: remove outdated comment that is no longer true
build: replace some addprefix/addsuffix with substitution refs
avutil: Remove unused arbitrary precision integer code.
configure: Drop check for availability of ten assembler operands.
aacenc: Save channel configuration for later use.
aacenc: Fix codebook trellising for zeroed bands.
swscale: change prototypes of scaled YUV output functions.
swscale: re-add support for non-native endianness.
swscale: disentangle yuv2rgbX_c_full() into small functions.
swscale: split yuv2packed[12X]_c() remainders into small functions.
swscale: split yuv2packedX_altivec in smaller functions.
...
Conflicts:
Makefile
configure
libavcodec/x86/dsputil_mmx.c
libavfilter/Makefile
libavformat/Makefile
libavutil/integer.c
libavutil/integer.h
libswscale/swscale.c
libswscale/swscale_internal.h
libswscale/x86/swscale_template.c
tests/ref/lavfi/pixdesc_le
tests/ref/lavfi/pixfmts_scale
Merged-by: Michael Niedermayer <michaelni@gmx.at>
They introduce too much complexity for very little benefit. The result is that
encoding will be more likely to fail at extremely low bitrates where quality
would be awful anyway.
* qatar/master:
swscale: remove misplaced comment.
ffmpeg: fix streaming to ffserver.
swscale: split out RGB48 output functions from yuv2packed[12X]_c().
build: move vpath directives to main Makefile
swscale: fix JPEG-range YUV scaling artifacts.
build: move ALLFFLIBS to a more logical place
ARM: factor some repetitive code into macros
Fix SVQ3 after adding 4:4:4 H.264 support
H.264: fix CODEC_FLAG_GRAY
4:4:4 H.264 decoding support
ac3enc: fix allocation of floating point samples.
Conflicts:
ffmpeg.c
libavcodec/dsputil_template.c
libavcodec/h264.c
libavcodec/mpegvideo.c
libavcodec/snow.c
libswscale/swscale.c
libswscale/swscale_internal.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master: (24 commits)
utils: Drop pointless '#if 1' preprocessor directive.
ac3enc: remove empty ac3_float function that is never called
ac3enc: split templated float vs. fixed functions into a separate file.
ac3enc: dynamically allocate AC3EncodeContext fields windowed_samples and mdct
ac3enc: use function pointer to choose between AC-3 and E-AC-3 header output functions.
Roll back 4:4:4 H.264 for now Needs some ARM/PPC asm modifications.
Fix SVQ3 after adding 4:4:4 H.264 support
H.264: fix CODEC_FLAG_GRAY
4:4:4 H.264 decoding support
h264_parser: Fix whitespace after previous change.
h264_parser: Fix behaviour when PARSER_FLAG_COMPLETE_FRAMES is set.
wav: remove an invalid free().
lavf: initialise reference_dts in av_estimate_timings_from_pts.
h264: don't be so picky on decoding pps in extradata.
avcodec.h: add or elaborate on some documentation comments.
h264: change a few comments into error messages
ac3dec: fix doxy-style for comment ("///>" should be "///<" instead).
img2: add .dpx to the list of supported file extensions.
ffv1: fix undefined behavior with insane widths.
ARM: jrevdct_arm: simplify stack usage
...
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* 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>
* 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>
Aligned local variables must use the LOCAL_ALIGNED macro to ensure
correct alignment on all systems. The unusual size argument to
memset is required since the implementation of LOCAL_ALIGNED may
use a pointer to an array.
Signed-off-by: Mans Rullgard <mans@mansr.com>
* 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>
Uninitialized coefficients were being used to generate exponents, some
of which actually ended up in the final stream. Even though, they were
just extra exponents that are not used by any decoder, it is still
better to have consistent output for testing. This also fixes valgrind
errors.
* 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.
* qatar/master: (33 commits)
rtpdec_qdm2: Don't try to parse data packet if no configuration is received
ac3enc: put the counting of stereo rematrixing bits in the same place to make the code easier to understand.
ac3enc: clean up count_frame_bits() and count_frame_bits_fixed()
mpegvideo: make FF_DEBUG_DCT_COEFF output coeffs via av_log() instead of just via AVFrame.
srtdec: make sure we don't write past the end of buffer
wmaenc: improve channel count and bitrate error handling in encode_init()
matroskaenc: make sure we don't produce invalid file with no codec ID
matroskadec: check that pointers were initialized before accessing them
lavf: fix function name in compute_pkt_fields2 av_dlog message
lavf: fix av_find_best_stream when providing a wanted stream.
lavf: fix av_find_best_stream when decoder_ret is given and using a related stream.
ffmpeg: factorize quality calculation
tiff: add support for SamplesPerPixel tag in tiff_decode_tag()
tiff: Prefer enum TiffCompr over int for TiffContext.compr.
mov: Support edit list atom version 1.
configure: Enable libpostproc automatically if GPL code is enabled.
Cosmetics: fix prototypes in oggdec
oggdec: fix memleak with continuous streams.
matroskaenc: add missing new line in av_log() call
dnxhdenc: add AVClass in private context.
...
swscale changes largely rewritten by me or replaced by baptsites due to lots of bugs in ronalds code.
Above code is also just in case its not obvios to a large extended duplicates that where cherry picked
from ffmpeg.
Conflicts:
configure
ffmpeg.c
libavformat/matroskaenc.c
libavutil/pixfmt.h
libswscale/ppc/swscale_template.c
libswscale/swscale.c
libswscale/swscale_template.c
libswscale/utils.c
libswscale/x86/swscale_template.c
tests/fate/h264.mak
tests/ref/lavfi/pixdesc_le
tests/ref/lavfi/pixfmts_copy_le
tests/ref/lavfi/pixfmts_null_le
tests/ref/lavfi/pixfmts_scale_le
tests/ref/lavfi/pixfmts_vflip_le
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* 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>
* 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>
* qatar/master:
vorbisdec: Rename silly "class_" variable to plain "class".
simple_idct_alpha: Drop some useless casts.
Simplify av_log_missing_feature().
ac3enc: remove check for mismatching channels and channel_layout
If AVCodecContext.channels is 0 and AVCodecContext.channel_layout is non-zero, set channels based on channel_layout.
If AVCodecContext.channel_layout and AVCodecContext.channels are both non-zero, check to make sure they do not contradict eachother.
cosmetics: indentation
Check AVCodec.supported_samplerates and AVCodec.channel_layouts in avcodec_open().
aacdec: remove sf_scale and sf_offset.
aacdec: use a scale of 2 in the LTP MDCT rather than doubling the coefficient table values from the spec.
Define POW_SF2_ZERO in aac.h and use for ff_aac_pow2sf_tabp[] offsets instead of hardcoding 200 everywhere.
Large intensity stereo and PNS indices are legal. Clip them instead of erroring out. A magnitude of 100 corresponds to 2^25 so the will most likely result in clipped output anyway.
qpeg: use reget_buffer() in decode_frame()
ultimotion: use reget_buffer() in ulti_decode_frame()
smacker: remove unnecessary call to avctx->release_buffer in decode_frame()
avparser: don't av_malloc(0).
Merged-by: Michael Niedermayer <michaelni@gmx.at>
There is no need to have 2 encoders, the input sample format can,does and should choose which is used
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master: (22 commits)
ac3enc: move extract_exponents inner loop to ac3dsp
avio: deprecate url_get_filename().
avio: deprecate url_max_packet_size().
avio: make url_get_file_handle() internal.
avio: make url_filesize() internal.
avio: make url_close() internal.
avio: make url_seek() internal.
avio: cosmetics, move AVSEEK_SIZE/FORCE declarations together
avio: make url_write() internal.
avio: make url_read_complete() internal.
avio: make url_read() internal.
avio: make url_open() internal.
avio: make url_connect internal.
avio: make url_alloc internal.
applehttp: Merge two for loops
applehttp: Restructure the demuxer to use a custom AVIOContext
applehttp: Move finished and target_duration to the variant struct
aacenc: reduce the number of loop index variables
avio: deprecate url_open_protocol
avio: deprecate url_poll and URLPollEntry
...
Conflicts:
libavformat/applehttp.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* qatar/master:
fate: fix partial run when no samples path is specified
ARM: NEON fixed-point forward MDCT
ARM: NEON fixed-point FFT
lavf: bump minor version and add an APIChanges entry for avio changes
avio: simplify url_open_dyn_buf_internal by using avio_alloc_context()
avio: make url_fdopen internal.
avio: make url_open_dyn_packet_buf internal.
avio: avio_ prefix for url_close_dyn_buf
avio: avio_ prefix for url_open_dyn_buf
avio: introduce an AVIOContext.seekable field
ac3enc: use generic fixed-point mdct
lavfi: add fade filter
Change yadif to not use out of picture lines.
lavc: deprecate AVCodecContext.antialias_algo
lavc: mark mb_qmin/mb_qmax for removal on next major bump.
Conflicts:
doc/filters.texi
libavcodec/ac3enc_fixed.h
libavcodec/ac3enc_float.h
libavfilter/Makefile
libavfilter/allfilters.c
libavfilter/vf_fade.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This makes the AC3 encoder use the shared fixed-point MDCT rather
than its own implementation. The checksum changes are due to
different rounding in the MDCT.
Signed-off-by: Mans Rullgard <mans@mansr.com>
* newdev/master:
mpegts: propagate avio EOF in read_packet()
configure: Initial support for --target-os=symbian
Fixed-point FFT and MDCT
Include dependencies for test programs
ac3enc: simplify sym_quant()
flvdec: read index stored in the 'keyframes' tag.
mov: Add support for zero-sized stsc runs.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
These expressions are equivalent since levels is always odd, and
overflow is impossible due to the constraints set by the assert().
Signed-off-by: Mans Rullgard <mans@mansr.com>
* newdev/master:
ac3enc: move compute_mantissa_size() to ac3dsp
ac3enc: move mant*_cnt and qmant*_ptr out of AC3EncodeContext
Remove support for stripping executables
ac3enc: NEON optimised float_to_fixed24
ac3: move ff_ac3_bit_alloc_calc_bap to ac3dsp
dfa: protect pointer range checks against overflows.
Duplicate: mimic: implement multithreading.
Merged-by: Michael Niedermayer <michaelni@gmx.at>
These fields are only used in quantize_mantissas() and reset
on each call, no need to store them in the main context.
Signed-off-by: Mans Rullgard <mans@mansr.com>
* newdev/master:
ac3enc: avoid memcpy() of exponents and baps in EXP_REUSE case by using exponent reference blocks.
Chronomaster DFA decoder
DUPLICATE: framebuffer device demuxer
NOT MERGED: cosmetics: fix dashed line length after 070c5d0
http: header field names are case insensitive
Conflicts:
LICENSE
README
doc/indevs.texi
libavdevice/fbdev.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* newdev/master:
ac3enc: Add codec-specific options for writing AC-3 metadata.
NOT MERGED: Remove arrozcru URL from documentation
sndio support for playback and record
Conflicts:
doc/faq.texi
doc/general.texi
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* newdev/master:
mov: set audio service type for AC-3 from bitstream mode in the 'dac3' atom.
Get audio_service_type for AC-3 based on bitstream mode in the AC-3 parser and decoder, and vice-versa for the AC-3 encoder.
Use audio_service_type to set stream disposition.
Add APIchanges entry for audio_service_type.
Add audio_service_type field to AVCodecContext for encoding and reporting of the service type in the audio bitstream.
configure: in check_ld, place new -l flags before existing ones
support @heading, @subheading, @subsubheading, and @subsubsection in texi2pod.pl
doc: update build system documentation
aacenc: indentation
aacenc: fix the side calculation in search_for_ms
vp8.c: rename EDGE_* to VP8_EDGE_*.
Conflicts:
doc/APIchanges
libavcodec/avcodec.h
libavcodec/version.h
libavcodec/vp8.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* newdev/master:
avio: make udp_set_remote_url/get_local_port internal.
asfdec: also subtract preroll when reading simple index object
matroskaenc: remove a variable that's unused after bc17bd9.
avio: cosmetics - nicer vertical alignment.
Remove unnecessary icc version checks
Disable 'attribute "foo" ignored' warnings from icc
rtsp: Don't use a locale dependent format string
Add xd55 codec tag for XDCAM HD422 720p25 CBR files.
configure: get libavcodec version from new version.h header
lavc: move the version macros to a new installed header.
matroskaenc: simplify get_aac_sample_rates by using ff_mpeg4audio_get_config
Do not use format string "%0.3f" for RTSP Range field.
Add apply_window_int16() to DSPContext with x86-optimized versions and use it in the ac3_fixed encoder.
Document usage of import libraries created by dlltool
configure: Set the correct lib target for arm/wince dlltool
fate: simplify regression-funcs.sh
fate: add support for multithread testing
Conflicts:
libavformat/rtspdec.c
libavutil/attributes.h
libavutil/internal.h
libavutil/mem.h
Merged-by: Michael Niedermayer <michaelni@gmx.at>
* newdev/master: (33 commits)
Fix an infinite loop when RoQ encoded generated a frame with a size greater than the maximum valid size.
Add kbdwin.o to AC3 decoder
Detect byte-swapped AC-3 and support decoding it directly.
cosmetics: indentation
Always copy input data for AC3 decoder.
ac3enc: make sym_quant() branch-free
cosmetics: indentation
Add a CPU flag for the Atom processor.
id3v2: skip broken tags with invalid size
id3v2: don't explicitly skip padding
Make sure kbhit() is in conio.h
fate: update wmv8-drm reference
vc1: make P-frame deblock filter bit-exact.
configure: Add the -D parameter to the dlltool command
amr: Set the AVFMT_GENERIC_INDEX flag
amr: Set the pkt->pos field properly to the start of the packet
amr: Set the codec->bit_rate field based on the last packet
rtsp: Specify unicast for TCP interleaved streams, too
Set the correct target for mingw64 dlltool
applehttp: Change the variable for stream position in seconds into int64_t
...
Conflicts:
ffmpeg.c
ffplay.c
libavcodec/ac3dec.c
libavformat/avio.h
libavformat/id3v2.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>
This increases the accuracy of coefficients, leading to improved quality.
Rescaling of the coefficients to full 25-bit accuracy is done rather than
offsetting the exponent values. This requires coefficient scaling to be done
before determining the rematrixing strategy. Also, the rematrixing strategy
calculation must use 64-bit math to prevent overflow due to the higher
precision coefficients.
Currently it is always 4, but this change will allow it to be adjusted when
bandwidth-related features are added such as channel coupling, enhanced
channel coupling, and spectral extension.
The rematrixing strategy reuse flags are not reset between frames, so they
need to be initialized for all blocks, not just block 0.
Signed-off-by: Mans Rullgard <mans@mansr.com>
This is to match the value in every (E-)AC-3 file from commercial sources.
It has a negligible effect on audio quality.
Signed-off-by: Mans Rullgard <mans@mansr.com>
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
This patch changes the exponent difference threshold in the exponent
strategy decision function of the AC-3 encoder. I tested lowering in
increments of 100. From 1000 down to 500 generally increased in quality
with each step, but 400 was generally much worse.
Signed-off-by: Mans Rullgard <mans@mansr.com>
exponent strategies for a single channel to compute_exp_strategy_ch().
This allows for removal of the temporary pointer arrays.
Originally committed as revision 26356 to svn://svn.ffmpeg.org/ffmpeg/trunk
