Converting to FLV Using FFMPEG

by Little Bear @31 ก.ค. 53 14:01 ( IP : 61...56 ) | Tags : Convert , ffmpeg , flv

เคยแปลงโดยใช้ mencoder อยู่พักนึง รู้สึกว่าใช้ยาก เลยลองเปลี่ยนเป็น ffmpeq บ้าง

แปลงจาก MPG เป็น FLV โดยใช้ค่า default ทุกอย่าง

ffmpeg -i input.mpg -f flv output.flv

เชื่อมไฟล์เข้าด้วยกันด้วยคุณภาพเหมือนต้นฉบับ

ffmpeg -i concat:"input1.mpg|input2.mpg" -sameq output.mpg
ffmpeg -i concat:"input1.mpg|input2.mpg" -b 1000000 -f flv output.flv
ffmpeg -i concat:"input1.mpg|input2.mpg" -vcodec libx264 -threads 3 -b 1000000 -f flv output.flv

ปรับขนาดให้เล็กลงสักหน่อย เพราะเน็ตผมช้า เหลือคุณภาพเสียง 22kHz bitrate 400kbps

ffmpeg -i input.mpg -ar 22050 -b 400000 output.flv

แปลงโดยใช้ codec h.264 ซึ่งจะได้คุณภาพที่ดีกว่า

ffmpeg -i input.mpg -vcodec libx264 -vpre slow -ar 22050 -threads 3 -s 640x360 -aspect 16:9 -ss 00:00:00 -vb 300000 -metadata title="Title here" output.flv

you can also use mpgtx (install it via APT) then just

mpgtx -j file01.mpg file02.mpg -o output_name.mpg



แหล่งเรียนรู้

พารามิเตอร์ที่ใช้บ่อย

`-ss position'  : เริ่มต้นที่เวลา position ในหน่วยวินาที หรือใช้รูปแบบ hh:mm:ss[.xxx] ก็ได้

`-t duration' : Restrict the transcoded/captured video sequence to the duration specified in seconds. hh:mm:ss[.xxx] syntax is also supported.

`-aspect aspect' : Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).

`-s size' : กำหนดขนาดของวีดิโอ เช่น HD มีขนาด 425x240 , 480x270 , 640x360 , 852x480 , 1280x720 , 1920x1080 หรือจะใช้ hd480 , hd720 , hd1080 ก็ได้

  • cif 352x288
  • 4cif 704x576
  • qvga 320x240
  • vga 640x480
  • sqcif 128x96
  • qcif 176x144
  • cif 352x288
  • 4cif 704x576
  • 16cif 1408x1152
  • qqvga 160x120
  • qvga 320x240
  • vga 640x480
  • svga 800x600
  • xga 1024x768
  • uxga 1600x1200
  • qxga 2048x1536
  • sxga 1280x1024
  • qsxga 2560x2048
  • hsxga 5120x4096
  • wvga 852x480
  • wxga 1366x768
  • wsxga 1600x1024
  • wuxga 1920x1200
  • woxga 2560x1600
  • wqsxga 3200x2048
  • wquxga 3840x2400
  • whsxga 6400x4096
  • whuxga 7680x4800
  • cga 320x200
  • ega 640x350
  • hd480 852x480
  • hd720 1280x720
  • hd1080 1920x1080

ffmpeg manual

NAME ffmpeg – FFmpeg video converter

SYNOPSIS ffmpeg [[infile options]***hh:mm:ss[.xxx]” syntax is also supported. This option affects all the input files that follow it. The offset is added to the timestamps of the input files. Specifying a posi‐ tive offset means that the corresponding streams are delayed by ’offset’ seconds.

Video Options

-b bitrate Set the video bitrate in kbit/s (default = 200 kb/s). -r fps Set frame rate (default = 25).

-s size Set frame size. The format is wxh (default = 160×128). The following abbreviations are recognized:

sqcif 128×96

qcif 176×144

cif 352×288

4cif 704×576

-aspect aspect Set aspect ratio (4:3, 16:9 or 1.3333, 1.7777).

-croptop size Set top crop band size (in pixels).

-cropbottom size Set bottom crop band size (in pixels).

-cropleft size Set left crop band size (in pixels).

-cropright size Set right crop band size (in pixels).

-padtop size Set top pad band size (in pixels).

-padbottom size Set bottom pad band size (in pixels). -padleft size Set left pad band size (in pixels).

-padright size Set right pad band size (in pixels).

-padcolor (hex color) Set color of padded bands. The value for padcolor is expressed as a six digit hexadecimal number where the first two digits represent red, the middle two digits green and last two digits blue (default = 000000 (black)).

-vn Disable video recording.

-bt tolerance Set video bitrate tolerance (in kbit/s).

-maxrate bitrate Set max video bitrate tolerance (in kbit/s).

-minrate bitrate Set min video bitrate tolerance (in kbit/s).

-bufsize size Set rate control buffer size (in kbit).

-vcodec codec Force video codec to codec. Use the “copy” special value to tell that the raw codec data must be copied as is.

-sameq Use same video quality as source (implies VBR).

-pass n Select the pass number (1 or 2). It is useful to do two pass encoding. The statistics of the video are recorded in the first pass and the video is generated at the exact requested bitrate in the second pass.

-passlogfile file Set two pass logfile name to file. Advanced Video Options

-g gop_size Set the group of pictures size.

-intra Use only intra frames.

-qscale q Use fixed video quantiser scale (VBR).

-qmin q minimum video quantiser scale (VBR)

-qmax q maximum video quantiser scale (VBR)

-qdiff q maximum difference between the quantiser scales (VBR)

-qblur blur video quantiser scale blur (VBR)

-qcomp compression video quantiser scale compression (VBR)

-rcinitcplx complexity initial complexity for single pass encoding

-b_qfactor factor qp factor between P- and B-frames

-i_qfactor factor qp factor between P- and I-frames

-bqoffset offset qp offset between P- and B-frames -iqoffset offset qp offset between P- and I-frames

-rc_eq equation Set rate control equation (default = “tex^qComp”).

-rc_override override rate control override for specific intervals

-me method Set motion estimation method to method. Available methods are (from lowest to best quality):

zero Try just the (0, 0) vector.

phods log x1 epzs (default method)

full exhaustive search (slow and marginally better than epzs)

-dct_algo algo Set DCT algorithm to algo. Available values are:

0 FFDCTAUTO (default)

1 FFDCTFASTINT

2 FFDCTINT

3 FFDCTMMX

4 FFDCTMLIB

5 FFDCTALTIVEC

-idct_algo algo Set IDCT algorithm to algo. Available values are:

0 FFIDCTAUTO (default)

1 FFIDCTINT

2 FFIDCTSIMPLE

3 FFIDCTSIMPLEMMX

4 FFIDCTLIBMPEG2MMX

5 FFIDCTPS2

6 FFIDCTMLIB

7 FFIDCTARM

8 FFIDCTALTIVEC

9 FFIDCTSH4

10 FFIDCTSIMPLEARM

-er n Set error resilience to n.

1 FFERCAREFUL (default)

2 FFERCOMPLIANT

3 FFERAGGRESSIVE

4 FFERVERY_AGGRESSIVE

-ec bitmask Set error concealment to bitmask. bit_mask is a bit mask of the following values:

1 FFECGUESS_MVS (default = enabled)

2 FFECDEBLOCK (default = enabled)

-bf frames Use ’frames’ B-frames (supported for MPEG-1, MPEG-2 and MPEG-4).

-mbd mode macroblock decision

0 FFMBDECISIONSIMPLE: Use mbcmp (cannot change it yet in FFmpeg).

1 FFMBDECISION_BITS: Choose the one which needs the fewest bits.

2 FFMBDECISION_RD: rate distortion

-4mv Use four motion vector by macroblock (MPEG-4 only).

-part Use data partitioning (MPEG-4 only).

-bug param Work around encoder bugs that are not auto-detected.

-strict strictness How strictly to follow the standards.

-aic Enable Advanced intra coding (h263+).

-umv Enable Unlimited Motion Vector (h263+)

-deinterlace Deinterlace pictures.

-interlace Force interlacing support in encoder (MPEG-2 and MPEG-4 only). Use this option if your input file is inter‐ laced and you want to keep the interlaced format for minimum losses. The alternative is to deinterlace the input stream with -deinterlace, but deinterlacing introduces losses.

-psnr Calculate PSNR of compressed frames.

-vstats Dump video coding statistics to vstats_HHMMSS.log.

-vhook module Insert video processing module. module contains the module name and its parameters separated by spaces.

Audio Options

-ar freq Set the audio sampling frequency (default = 44100 Hz).

-ab bitrate Set the audio bitrate in kbit/s (default = 64).

-ac channels Set the number of audio channels (default = 1).

-an Disable audio recording.

-acodec codec Force audio codec to codec. Use the “copy” special value to specify that the raw codec data must be copied as is.

Audio/Video grab options

-vd device sEt video grab device (e.g. /dev/video0).

-vc channel Set video grab channel (DV1394 only).

-tvstd standard Set television standard (NTSC, PAL (SECAM)).

-dv1394 Set DV1394 grab.

-ad device Set audio device (e.g. /dev/dsp).

Advanced options

-map file:stream Set input stream mapping.

-debug Print specific debug info.

-benchmark Add timings for benchmarking.

-hex Dump each input packet.

-bitexact Only use bit exact algorithms (for codec testing).

-ps size Set packet size in bits.

-re Read input at native frame rate. Mainly used to simulate a grab device.

-loop Loop over the input stream. Currently it works only for image streams. This option is used for automatic FFserver testing.

-loopoutput numberof_times Repeatedly loop output for formats that support looping such as animated GIF (0 will loop the output infinitely).

-vsync parameter Video sync method. Video will be stretched/squeezed to match the timestamps, it is done by duplicating and dropping frames. With -map you can select from which stream the timestamps should be taken. You can leave either video or audio unchanged and sync the remaining stream(s) to the unchanged one.

-async samplespersecond Audio sync method. “Stretches/squeezes” the audio stream to match the timestamps, the parameter is the maximum samples per second by which the audio is changed. -async 1 is a special case where only the start of the audio stream is corrected without any later correction.

FFmpeg formula evaluator

When evaluating a rate control string, FFmpeg uses an internal formula evaluator.

The following binary operators are available: “+”, “-”, “*”, “/”, “^”.

The following unary operators are available: “+”, “-”, “(…)”.

The following functions are available:

sinh(x) cosh(x) tanh(x) sin(x) cos(x) tan(x) exp(x) log(x) squish(x) gauss(x) abs(x) max(x, y) min(x, y) gt(x, y) lt(x, y) eq(x, y) bits2qp(bits) qp2bits(qp)

The following constants are available:

PI E iTex pTex tex mv fCode iCount mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex avgTex

EXAMPLES Video and Audio grabbing

FFmpeg can use a video4linux compatible video source and any Open Sound System audio source:

ffmpeg /tmp/out.mpg

Note that you must activate the right video source and channel before launching FFmpeg with any TV viewer such as xawtv () by Gerd Knorr. You also have to set the audio recording levels correctly with a standard mixer. Video and Audio file format conversion

  • FFmpeg can use any supported file format and protocol as input:

Examples:

  • You can use YUV files as input:

ffmpeg -i /tmp/test%d.Y /tmp/out.mpg

It will use the files:

/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V, /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc…

The Y files use twice the resolution of the U and V files. They are raw files, without header. They can be gener‐ ated by all decent video decoders. You must specify the size of the image with the -s option if FFmpeg cannot guess it.

  • You can input from a raw YUV420P file:

ffmpeg -i /tmp/test.yuv /tmp/out.avi

test.yuv is a file containing raw YUV planar data. Each frame is composed of the Y plane followed by the U and V planes at half vertical and horizontal resolution.

  • You can output to a raw YUV420P file:

ffmpeg -i mydivx.avi hugefile.yuv

  • You can set several input files and output files:

ffmpeg -i /tmp/a.wav -s 640×480 -i /tmp/a.yuv /tmp/a.mpg

Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.

  • You can also do audio and video conversions at the same time:
  • You can set several input files and output files:

ffmpeg -i /tmp/a.wav -s 640×480 -i /tmp/a.yuv /tmp/a.mpg

Converts the audio file a.wav and the raw YUV video file a.yuv to MPEG file a.mpg.

  • You can also do audio and video conversions at the same time:

ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2

Converts a.wav to MPEG audio at 22050Hz sample rate.

  • You can encode to several formats at the same time and define a mapping from input stream to output streams:

ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0

Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map file:index’ specifies which input stream is used for each output stream, in the order of the definition of output streams.

  • You can transcode decrypted VOBs

ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi

This is a typical DVD ripping example; the input is a VOB file, the output an AVI file with MPEG-4 video and MP3 audio. Note that in this command we use B-frames so the MPEG-4 stream is DivX5 compatible, and GOP size is 300 which means one intra frame every 10 seconds for 29.97fps input video. Furthermore, the audio stream is MP3-encoded so you need to enable LAME support by passing “–enable-mp3lame” to configure. The mapping is partic‐ ularly useful for DVD transcoding to get the desired audio language.

NOTE: To see the supported input formats, use “ffmpeg -formats”.

SEE ALSO ffserver(1), ffplay(1) and the HTML documentation of ffmpeg.

AUTHOR Fabrice Bellard 2007-01-28

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