我正在使用 ffmpeg 将视频转码为特定的 AVI 格式ffmpeg.exe -i "Input.ext" -y -vcodec rawvideo -pix_fmt rgb555le -an -map_metadata -1 TEST_ENCODE.avi。生成的 AVI 是不再支持的旧命令行程序的输入。不幸的是，尽管格式正确并使用了正确的编码，但该程序无法读取由 ffmpeg 生成的 AVI。经过几天的分析和调试，我终于确定了问题所在。ffmpeg 使用负高度对 AVI 中的位图帧进行编码，表示自上而下的扫描线顺序。但我的其他程序需要正高度和更传统的自下而上的扫描线顺序。是否可以强制 ffmpeg 对帧使用正高度（自下而上的扫描线顺序）？
编辑：即使将详细程度调高到尽可能高，我仍然无法让 ffmpeg 报告足够的细节来捕捉编码中这个通常不重要的细节，但由于我被要求提供日志，我会提供它们。
在旧版应用程序中工作：
D:\AutoHotkey Scripts\PS Gui v4\!OutputDest>"D:\Program Files\ffmpeg\bin\ffmpeg.exe" -v 9 -loglevel 99 -i TEST_COPY.avi
ffmpeg version git-2020-06-17-0b3bd00 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3.1 (GCC) 20200523
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
libavutil 56. 55.100 / 56. 55.100
libavcodec 58. 92.100 / 58. 92.100
libavformat 58. 46.101 / 58. 46.101
libavdevice 58. 11.100 / 58. 11.100
libavfilter 7. 86.100 / 7. 86.100
libswscale 5. 8.100 / 5. 8.100
libswresample 3. 8.100 / 3. 8.100
libpostproc 55. 8.100 / 55. 8.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
Reading option '-i' ... matched as input url with argument 'TEST_COPY.avi'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument 9.
Successfully parsed a group of options.
Parsing a group of options: input url TEST_COPY.avi.
Successfully parsed a group of options.
Opening an input file: TEST_COPY.avi.
[NULL @ 000002d12df7bf80] Opening 'TEST_COPY.avi' for reading
[file @ 000002d12df7c880] Setting default whitelist 'file,crypto,data'
Probing avi score:100 size:2048
[avi @ 000002d12df7bf80] Format avi probed with size=2048 and score=100
[avi @ 000002d12df7d300] use odml:1
[avi @ 000002d12df7bf80] pos:14 tag: tag=LIST size=0x11ec
[avi @ 000002d12df7bf80] pos:18 list: tag=hdrl size=0x0
[avi @ 000002d12df7bf80] pos:20 tag: tag=avih size=0x38
[avi @ 000002d12df7bf80] pos:60 tag: tag=LIST size=0x1094
[avi @ 000002d12df7bf80] pos:64 list: tag=strl size=0x0
[avi @ 000002d12df7bf80] pos:6C tag: tag=strh size=0x38
[avi @ 000002d12df7bf80] pos:74 strh: tag=vids size=0xffffffff
[avi @ 000002d12df7bf80] 125000 8341 0
[avi @ 000002d12df7bf80] pos:AC tag: tag=strf size=0x28
[avi @ 000002d12df7bf80] pos:D4 video: tag=[0][0][0][0] size=0x0
[avi @ 000002d12df7bf80] pos:DC tag: tag=JUNK size=0x1018
[avi @ 000002d12df7bf80] pos:10FC tag: tag=JUNK size=0x104
[avi @ 000002d12df7bf80] pos:1208 tag: tag=LIST size=0x1a
[avi @ 000002d12df7bf80] pos:120C list: tag=INFO size=0x0
[avi @ 000002d12df7bf80] pos:122A tag: tag=JUNK size=0x3f8
[avi @ 000002d12df7bf80] pos:162A tag: tag=LIST size=0x4268644
[avi @ 000002d12df7bf80] pos:162E list: tag=movi size=0x0
[avi @ 000002d12df7bf80] movi end=4269c6e
[avi @ 000002d12df7bf80] movi_end=0x4269c6e
[avi @ 000002d12df7bf80] 0: tag=0x63643030 flags=0x10 pos=0x4 len=348160/348160 cum_len=0
[avi @ 000002d12df7bf80] 1: tag=0x63643030 flags=0x10 pos=0x5500c len=348160/348160 cum_len=1
[avi @ 000002d12df7bf80] 2: tag=0x63643030 flags=0x10 pos=0xaa014 len=348160/348160 cum_len=2
[A bunch more of these, truncated due to size.]
[avi @ 000002d12df7bf80] 198: tag=0x63643030 flags=0x10 pos=0x41be634 len=348160/348160 cum_len=198
[avi @ 000002d12df7bf80] 199: tag=0x63643030 flags=0x10 pos=0x421363c len=348160/348160 cum_len=199
[avi @ 000002d12df7bf80] Before avformat_find_stream_info() pos: 5678 bytes read:104712 seeks:4 nb_streams:1
[avi @ 000002d12df7bf80] parser not found for codec rawvideo, packets or times may be invalid.
Last message repeated 1 times
[avi @ 000002d12df7bf80] All info found
[avi @ 000002d12df7bf80] stream 0: start_time: 0 duration: 13.3456
[avi @ 000002d12df7bf80] format: start_time: 0 duration: 13.3456 (estimate from stream) bitrate=41747 kb/s
[avi @ 000002d12df7bf80] After avformat_find_stream_info() pos: 353846 bytes read:420112 seeks:4 frames:1
Input #0, avi, from 'TEST_COPY.avi':
Metadata:
encoder : Lavf58.46.101
Duration: 00:00:13.35, start: 0.000000, bitrate: 41747 kb/s
Stream #0:0, 1, 8341/125000: Video: rawvideo, 1 reference frame, rgb555le, 640x272, 0/1, 41950 kb/s, 14.99 fps, 14.99 tbr, 14.99 tbn, 14.99 tbc
Successfully opened the file.
At least one output file must be specified
[AVIOContext @ 000002d12df85340] Statistics: 420112 bytes read, 4 seeks
TEST_ENCODE（不起作用）：
D:\AutoHotkey Scripts\PS Gui v4\!OutputDest>"D:\Program Files\ffmpeg\bin\ffmpeg.exe" -v 9 -loglevel 99 -i TEST_ENCODE.avi
ffmpeg version git-2020-06-17-0b3bd00 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3.1 (GCC) 20200523
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
libavutil 56. 55.100 / 56. 55.100
libavcodec 58. 92.100 / 58. 92.100
libavformat 58. 46.101 / 58. 46.101
libavdevice 58. 11.100 / 58. 11.100
libavfilter 7. 86.100 / 7. 86.100
libswscale 5. 8.100 / 5. 8.100
libswresample 3. 8.100 / 3. 8.100
libpostproc 55. 8.100 / 55. 8.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
Reading option '-i' ... matched as input url with argument 'TEST_ENCODE.avi'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument 9.
Successfully parsed a group of options.
Parsing a group of options: input url TEST_ENCODE.avi.
Successfully parsed a group of options.
Opening an input file: TEST_ENCODE.avi.
[NULL @ 000002c07a68bf80] Opening 'TEST_ENCODE.avi' for reading
[file @ 000002c07a68c880] Setting default whitelist 'file,crypto,data'
Probing avi score:100 size:2048
[avi @ 000002c07a68bf80] Format avi probed with size=2048 and score=100
[avi @ 000002c07a68d300] use odml:1
[avi @ 000002c07a68bf80] pos:14 tag: tag=LIST size=0x11ec
[avi @ 000002c07a68bf80] pos:18 list: tag=hdrl size=0x0
[avi @ 000002c07a68bf80] pos:20 tag: tag=avih size=0x38
[avi @ 000002c07a68bf80] pos:60 tag: tag=LIST size=0x1094
[avi @ 000002c07a68bf80] pos:64 list: tag=strl size=0x0
[avi @ 000002c07a68bf80] pos:6C tag: tag=strh size=0x38
[avi @ 000002c07a68bf80] pos:74 strh: tag=vids size=0xffffffff
[avi @ 000002c07a68bf80] 125000 8341 0
[avi @ 000002c07a68bf80] pos:AC tag: tag=strf size=0x28
[avi @ 000002c07a68bf80] pos:D4 video: tag=[0][0][0][0] size=0x0
[avi @ 000002c07a68bf80] pos:DC tag: tag=JUNK size=0x1018
[avi @ 000002c07a68bf80] pos:10FC tag: tag=JUNK size=0x104
[avi @ 000002c07a68bf80] pos:1208 tag: tag=LIST size=0x1a
[avi @ 000002c07a68bf80] pos:120C list: tag=INFO size=0x0
[avi @ 000002c07a68bf80] pos:122A tag: tag=JUNK size=0x3f8
[avi @ 000002c07a68bf80] pos:162A tag: tag=LIST size=0x4268644
[avi @ 000002c07a68bf80] pos:162E list: tag=movi size=0x0
[avi @ 000002c07a68bf80] movi end=4269c6e
[avi @ 000002c07a68bf80] movi_end=0x4269c6e
[avi @ 000002c07a68bf80] 0: tag=0x63643030 flags=0x10 pos=0x4 len=348160/348160 cum_len=0
[avi @ 000002c07a68bf80] 1: tag=0x63643030 flags=0x10 pos=0x5500c len=348160/348160 cum_len=1
[avi @ 000002c07a68bf80] 2: tag=0x63643030 flags=0x10 pos=0xaa014 len=348160/348160 cum_len=2
[A bunch more of these, truncated due to size.]
[avi @ 000002c07a68bf80] 198: tag=0x63643030 flags=0x10 pos=0x41be634 len=348160/348160 cum_len=198
[avi @ 000002c07a68bf80] 199: tag=0x63643030 flags=0x10 pos=0x421363c len=348160/348160 cum_len=199
[avi @ 000002c07a68bf80] Before avformat_find_stream_info() pos: 5678 bytes read:104712 seeks:4 nb_streams:1
[avi @ 000002c07a68bf80] parser not found for codec rawvideo, packets or times may be invalid.
Last message repeated 1 times
[avi @ 000002c07a68bf80] All info found
[avi @ 000002c07a68bf80] stream 0: start_time: 0 duration: 13.3456
[avi @ 000002c07a68bf80] format: start_time: 0 duration: 13.3456 (estimate from stream) bitrate=41747 kb/s
[avi @ 000002c07a68bf80] After avformat_find_stream_info() pos: 353846 bytes read:420112 seeks:4 frames:1
Input #0, avi, from 'TEST_ENCODE.avi':
Metadata:
encoder : Lavf58.46.101
Duration: 00:00:13.35, start: 0.000000, bitrate: 41747 kb/s
Stream #0:0, 1, 8341/125000: Video: rawvideo, 1 reference frame, rgb555le, 640x272, 0/1, 41950 kb/s, 14.99 fps, 14.99 tbr, 14.99 tbn, 14.99 tbc
Successfully opened the file.
At least one output file must be specified
[AVIOContext @ 000002c07a695340] Statistics: 420112 bytes read, 4 seeks
如您所见，ffmpeg 加载了“strf”块，但没有报告位图标头中每个字段的内容。为了获取该信息，我找到了一个名为 VidTrace 的漂亮小程序（http://www.jmcgowan.com/aviauthor.html#VidTrace）
在旧版应用程序中工作：
D:\AutoHotkey Scripts\PS Gui v4\!OutputDest>vidtrace.exe TEST_COPY.avi
RIFF (69642478) AVI
LIST (4588) hdrl
avih (56)
Microseconds Per Frame: 66728
14.986213 Frames Per Second
Maximum Bytes Per Second: 5243818
Pad to Multiples of This Size: 0
Flags DWORD (hex): 910
FLAG: (AVIF_HASINDEX) AVI File Has 'idx1' chunk
FLAG: (AVIF_ISINTERLEAVED) AVI File is Interleaved
FLAG: (AVIF_TRUSTCKTYPE) Use Chunk Type to Find Key Frames
Total Frames: 200
Initial Frames: 0
Number of Streams: 1
Suggested Buffer Size: 1048576
Width in Pixels: 640
Height in Pixels: 272
Scale (MAY BE UNUSED): 0
Rate (MAY BE UNUSED): 0
Samples Per Second (MAY BE UNUSED): 0
Start of AVI File (MAY BE UNUSED): 0
Length of AVI File (MAY BE UNUSED): 0
LIST (4244) strl
strh (56)
Stream Type (Four Character Code): 'vids'
'vids' is Four Character Code for Video Stream
Installable Compressor (Four Character Code): ''
'' is Four Character Code for Uncompressed DIB
Flags (hex): 0
Priority (MAY BE UNUSED) (hex): 0
Language Code (MAY BE UNUSED) (hex): 0
Initial Frames: 0
Scale: 8341
Rate: 125000
Start: 0
Length: 200
Suggested Buffer Size: 348160
Quality: 4294967295
Sample Size: 0
Frame - 16 bit RECT takes 8 bytes (MAY BE UNUSED): Top: 0 Bottom: 272 Left: 0 Right: 640
Note on Frame: In 16 bit Windows, the RECT structure is
Note on Frame: four (4) 16 bit integers, a total of 8 bytes.
Note on Frame: Some AVI use a 16 bit RECT for Frame.
Note on Frame: Others use a 32 bit RECT, a total of 16 bytes.
strf (40)
Windows Bitmap Header
Number of Bytes Required by Bitmap Structure: 40
Width of Bitmap in Pixels: 640
Height of Bitmap in Pixels: 272
Number of Planes: 1
Number of Bits Per Pixel (1,4,8,16,24, or 32): 16
Compression Mode (hex): 0
COMPRESSION: Uncompressed RGB Format
Size of Image in Bytes: 348160
Horizontal Resolution in Pixels per Meter: 0
Vertical Resolution in Pixels per Meter: 0
Number of Color Indices Actually Used by the Bitmap: 0
Number of Color Indices Considered Important to Display Bitmap: 0
JUNK (4120)
JUNK (260)
LIST (26) INFO
ISFT (14)
JUNK (1016)
LIST (69633604) movi
00dc (348160)
00dc (348160)
00dc (348160)
00dc (348160)
[A bunch more of these, truncated due to size.]
00dc (348160)
idx1 (3200)
TEST_ENCODE（不起作用）：
D:\AutoHotkey Scripts\PS Gui v4\!OutputDest>vidtrace.exe TEST_ENCODE.avi
RIFF (69642478) AVI
LIST (4588) hdrl
avih (56)
Microseconds Per Frame: 66728
14.986213 Frames Per Second
Maximum Bytes Per Second: 4891499
Pad to Multiples of This Size: 0
Flags DWORD (hex): 910
FLAG: (AVIF_HASINDEX) AVI File Has 'idx1' chunk
FLAG: (AVIF_ISINTERLEAVED) AVI File is Interleaved
FLAG: (AVIF_TRUSTCKTYPE) Use Chunk Type to Find Key Frames
Total Frames: 200
Initial Frames: 0
Number of Streams: 1
Suggested Buffer Size: 1048576
Width in Pixels: 640
Height in Pixels: 272
Scale (MAY BE UNUSED): 0
Rate (MAY BE UNUSED): 0
Samples Per Second (MAY BE UNUSED): 0
Start of AVI File (MAY BE UNUSED): 0
Length of AVI File (MAY BE UNUSED): 0
LIST (4244) strl
strh (56)
Stream Type (Four Character Code): 'vids'
'vids' is Four Character Code for Video Stream
Installable Compressor (Four Character Code): ''
'' is Four Character Code for Uncompressed DIB
Flags (hex): 0
Priority (MAY BE UNUSED) (hex): 0
Language Code (MAY BE UNUSED) (hex): 0
Initial Frames: 0
Scale: 8341
Rate: 125000
Start: 0
Length: 200
Suggested Buffer Size: 348160
Quality: 4294967295
Sample Size: 0
Frame - 16 bit RECT takes 8 bytes (MAY BE UNUSED): Top: 0 Bottom: 272 Left: 0 Right: 640
Note on Frame: In 16 bit Windows, the RECT structure is
Note on Frame: four (4) 16 bit integers, a total of 8 bytes.
Note on Frame: Some AVI use a 16 bit RECT for Frame.
Note on Frame: Others use a 32 bit RECT, a total of 16 bytes.
strf (40)
Windows Bitmap Header
Number of Bytes Required by Bitmap Structure: 40
Width of Bitmap in Pixels: 640
Height of Bitmap in Pixels: -272
Number of Planes: 1
Number of Bits Per Pixel (1,4,8,16,24, or 32): 16
Compression Mode (hex): 0
COMPRESSION: Uncompressed RGB Format
Size of Image in Bytes: 348160
Horizontal Resolution in Pixels per Meter: 0
Vertical Resolution in Pixels per Meter: 0
Number of Color Indices Actually Used by the Bitmap: 0
Number of Color Indices Considered Important to Display Bitmap: 0
JUNK (4120)
JUNK (260)
LIST (26) INFO
ISFT (14)
JUNK (1016)
LIST (69633604) movi
00dc (348160)
00dc (348160)
00dc (348160)
00dc (348160)
[A bunch more of these, truncated due to size.]
00dc (348160)
idx1 (3200)
请注意“strf”块中“以像素为单位的位图高度”值的不同符号。
我-vf vflip在编码时向 ffmpeg 添加了反转扫描线的功能，然后使用十六进制编辑器手动将位图高度编辑为正值。执行此操作后，我的旧程序可以正常运行，这证明负高度是导致我出现问题的唯一原因。
答案1
ffmpeg 需要更新才能生成具有正高度和自下而上扫描线顺序的 rawvideo AVI 视频帧。解决方案现在是使用命令-vf vflip -flipped_raw_rgb 1。