我正在尝试使用FFMPEG中的alpha通道将视频（mov）编码为flv，但我似乎无法使用
有谁知道如何设置它？
谢谢，
ffmpeg -i abc_btr_1280x800_Takeover.mov -vcodec flv -pix_fmt yuv444p -s 1280x800 test4.flv
这是报告......
ffmpeg started on 2013-10-25 at 15:47:30
Report written to "ffmpeg-20131025-154730.log"
Command line:
ffmpeg -i abc_btr_1280x800_Takeover.mov -vcodec flv -pix_fmt yuv444p -s 1280x800 test4.flv -report
ffmpeg version N-57367-g2f31b73 Copyright (c) 2000-2013 the FFmpeg developers
built on Oct 23 2013 20:34:17 with gcc 4.8.2 (GCC)
configuration: --disable-static --enable-shared --enable-gpl --enable-version3 -- disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r -- enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libcaca --enable- libfreetype --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame -- enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib
libavutil 52. 47.101 / 52. 47.101
libavcodec 55. 38.101 / 55. 38.101
libavformat 55. 19.104 / 55. 19.104
libavdevice 55. 4.100 / 55. 4.100
libavfilter 3. 89.100 / 3. 89.100
libswscale 2. 5.101 / 2. 5.101
libswresample 0. 17.104 / 0. 17.104
libpostproc 52. 3.100 / 52. 3.100
Splitting the commandline.
Reading option '-i' ... matched as input file with argument 'abc_btr_1280x800_Takeover.mov'.
Reading option '-vcodec' ... matched as option 'vcodec' (force video codec ('copy' to copy stream)) with argument 'flv'.
Reading option '-pix_fmt' ... matched as option 'pix_fmt' (set pixel format) with argument 'yuv444p'.
Reading option '-s' ... matched as option 's' (set frame size (WxH or abbreviation)) with argument '1280x800'.
Reading option 'test4.flv' ... matched as output file.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input file abc_btr_1280x800_Takeover.mov.
Successfully parsed a group of options.
Opening an input file: abc_btr_1280x800_Takeover.mov.
[mov,mp4,m4a,3gp,3g2,mj2 @ 000000000085ac00] Format mov,mp4,m4a,3gp,3g2,mj2 probed with size=2048 and score=100
[mov,mp4,m4a,3gp,3g2,mj2 @ 000000000085ac00] ISO: File Type Major Brand: qt
[mov,mp4,m4a,3gp,3g2,mj2 @ 000000000085ac00] File position before avformat_find_stream_info() is 281624339
[mov,mp4,m4a,3gp,3g2,mj2 @ 000000000085ac00] All info found
[mov,mp4,m4a,3gp,3g2,mj2 @ 000000000085ac00] File position after avformat_find_stream_info() is 288732
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'abc_btr_1280x800_Takeover.mov':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2013-09-22 02:50:18
Duration: 00:00:10.00, start: 0.000000, bitrate: 225299 kb/s
Stream #0:0(eng), 1, 1/24: Video: qtrle (rle / 0x20656C72), bgra, 1280x800, 225293 kb/s, SAR 1280:1280 DAR 8:5, 24 fps, 24 tbr, 24 tbn, 24 tbc (default)
Metadata:
creation_time : 2013-09-22 02:50:18
handler_name : Apple Alias Data Handler
timecode : 00:00:00:00
Stream #0:1(eng), 0, 1/24: Data: none (tmcd / 0x64636D74), 0 kb/s (default)
Metadata:
creation_time : 2013-09-22 02:50:22
handler_name : Apple Alias Data Handler
timecode : 00:00:00:00
Successfully opened the file.
Parsing a group of options: output file test4.flv.
Applying option vcodec (force video codec ('copy' to copy stream)) with argument flv.
Applying option pix_fmt (set pixel format) with argument yuv444p.
Applying option s (set frame size (WxH or abbreviation)) with argument 1280x800.
Successfully parsed a group of options.
Opening an output file: test4.flv.
Successfully opened the file.
detected 4 logical cores
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'video_size' to value '1280x800'
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'pix_fmt' to value '30'
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'time_base' to value '1/24'
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'pixel_aspect' to value '1280/1280'
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'sws_param' to value 'flags=2'
[graph 0 input from stream 0:0 @ 0000000000303bc0] Setting 'frame_rate' to value '24/1'
[graph 0 input from stream 0:0 @ 0000000000303bc0] w:1280 h:800 pixfmt:bgra tb:1/24 fr:24/1 sar:1/1 sws_param:flags=2
[scaler for output stream 0:0 @ 00000000003056a0] Setting 'w' to value '1280'
[scaler for output stream 0:0 @ 00000000003056a0] Setting 'h' to value '800'
[scaler for output stream 0:0 @ 00000000003056a0] Setting 'flags' to value '0x4'
[scaler for output stream 0:0 @ 00000000003056a0] w:1280 h:800 flags:'0x4' interl:0
Incompatible pixel format 'yuv444p' for codec 'flv', auto-selecting format 'yuv420p'
[format @ 00000000002f8320] compat: called with args=[yuv420p]
[format @ 00000000002f8320] Setting 'pix_fmts' to value 'yuv420p'
[AVFilterGraph @ 000000000085bc60] query_formats: 5 queried, 4 merged, 0 already done, 0 delayed
[scaler for output stream 0:0 @ 00000000003056a0] w:1280 h:800 fmt:bgra sar:1/1 -> w:1280 h:800 fmt:yuv420p sar:1/1 flags:0x4
[flv @ 0000000000374be0] intra_quant_bias = 0 inter_quant_bias = -64
Output #0, flv, to 'test4.flv':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
encoder : Lavf55.19.104
Stream #0:0(eng), 0, 1/1000: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p, 1280x800 [SAR 1:1 DAR 8:5], q=2-31, 200 kb/s, 1k tbn, 24 tbc (default)
Metadata:
creation_time : 2013-09-22 02:50:18
handler_name : Apple Alias Data Handler
timecode : 00:00:00:00
Stream mapping:
Stream #0:0 -> #0:0 (qtrle -> flv)
Press [q] to stop, [?] for help
frame= 27 fps=0.0 q=31.0 size= 351kB time=00:00:01.12 bitrate=2554.2kbits/s
frame= 46 fps= 45 q=31.0 size= 477kB time=00:00:01.91 bitrate=2039.5kbits/s
frame= 60 fps= 39 q=31.0 size= 543kB time=00:00:02.50 bitrate=1779.4kbits/s
frame= 74 fps= 36 q=31.0 size= 629kB time=00:00:03.08 bitrate=1672.4kbits/s
frame= 96 fps= 37 q=31.0 size= 795kB time=00:00:04.00 bitrate=1627.4kbits/s
frame= 123 fps= 40 q=31.0 size= 924kB time=00:00:05.12 bitrate=1477.0kbits/s
frame= 149 fps= 41 q=31.0 size= 1133kB time=00:00:06.20 bitrate=1494.7kbits/s
frame= 175 fps= 43 q=31.0 size= 1224kB time=00:00:07.29 bitrate=1375.5kbits/s
frame= 201 fps= 44 q=31.0 size= 1352kB time=00:00:08.37 bitrate=1322.7kbits/s
frame= 228 fps= 45 q=31.0 size= 1461kB time=00:00:09.50 bitrate=1260.1kbits/s
[output stream 0:0 @ 00000000003053c0] EOF on sink link output stream 0:0:default.
No more output streams to write to, finishing.
frame= 240 fps= 45 q=31.0 Lsize= 1600kB time=00:00:10.00 bitrate=1310.4kbits/s
video:1596kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.252476%
240 frames successfully decoded, 0 decoding errors
[AVIOContext @ 000000000032dfc0] Statistics: 3 seeks, 242 writeouts
[AVIOContext @ 000000000085bde0] Statistics: 281664506 bytes read, 3 seeks