移植MPlayer到linux 2.6的方法

使用的linux內(nèi)核為2.6.14.1 MPlayer版本為MPlayer-1.0pre7try2.bz2
目前雖然已經(jīng)添加了mad的mp3庫(kù)，但播放聲音文件回導(dǎo)致mplayer錯(cuò)誤，放視頻還得禁掉聲音.

下面介紹下整個(gè)移植過(guò)程，也是參考了網(wǎng)上很多文章綜合而來(lái)的
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1）編譯器最好選擇3.3.2 ，我使用3.4.1會(huì)出現(xiàn)snow.c編譯錯(cuò)誤，找不到解決辦法
解壓3.3.2到/usr/local/arm/下
并export PATH=/usr/local/arm/3.3.2/bin:$PATH
echo $PATH看看3.3.2是不是在第一個(gè)？

2）播放mp3需要禁掉mp3lib 而使用madlib ，據(jù)說(shuō)如果使用mp3lib會(huì)占用2000%的CPU，可能嘛？
安裝libmad
（1）.交叉編譯libmad
下載libmad包（libmad-0.15.1b.tar.gz）；
打開一個(gè)終端，進(jìn)入libmad的目錄，輸入配置命令：
./configure --enable-fpm=arm --host=arm-linux --disable-shared --disable-debugging --prefix=/usr/local/arm/3.3.2/lib
CC=arm-linux-gcc（要保證arm-linux-gcc的路徑已經(jīng)有 export過(guò)，否則給出完整路徑。）
make
make install
這樣就可以看到 /usr/local/arm/3.3.2/lib 目錄下多了include和lib目錄，這些就是libmad相關(guān)的庫(kù)。
（2）.在 configure mplayer的時(shí)候，要加上以下幾個(gè)選項(xiàng)：
--enable-mad
--with-extraincdir=/usr/local/arm/3.3.2/lib/include（這個(gè)指明 mad.h 這個(gè)文件所在的路徑）
--with-extralibdir=/usr/local/arm/3.3.2/lib/lib（這個(gè)指明libmad相關(guān)鏈接庫(kù)所在的路徑）
通過(guò)以上兩個(gè)步驟，就可以把libmad交叉編譯到 mplayer中。

3）解壓MPlayer-1.0pre7try2.bz2，改名為mplayer ，方便而已
在此目錄下配置
./configure?? --cc=arm-linux-gcc?? --target=arm-armv4-linux?? --enable-static?? --disable-win32???? --disable-dvdread?? --enable-fbdev?? --disable-mencoder?? --disable-live?? --disable-mp3lib?? --enable-mad?? --enable-libavcodec?? --with-extraincdir=/usr/local/arm/3.3.2/arm-linux/sys-include/:/usr/local/arm/3.3.2/lib/include --with-extralibdir=/usr/local/arm/3.3.2/arm-linux/lib:/usr/local/arm/3.3.2/lib/lib --prefix=/tmp/mplayer --host-cc=gcc

4）make
當(dāng)然會(huì)有錯(cuò)誤

排錯(cuò)

錯(cuò)誤（1）
./codec-cfg ./etc/codecs.conf > codecs.conf.h
./codec-cfg: 1: Syntax error: word unexpected (expecting ")")

網(wǎng)上有兩種解決方法
A 說(shuō)在configure時(shí)添加 --host-cc=gcc就可以解決
可是會(huì)出現(xiàn)其他庫(kù)找不到的錯(cuò)誤
猜想是指定了庫(kù)--with-extralibdir導(dǎo)致的，所以還得采用笨笨的B方案

B 引用原話
“ 先把mplayer編譯成x86的代碼，于是重新配置，簡(jiǎn)單的?? ./configure,?? make，然后將生成的codec－cfg改名為codec－cfg.x86。
然后再按跨平臺(tái)方式配置，編譯，等編譯器出現(xiàn)錯(cuò)誤停止編譯時(shí)，將codec－cfg.x86該名為codec－cfg，再make，OK,編譯就可以繼續(xù)進(jìn)行了。”
的確可行

錯(cuò)誤（2）vobsub.c錯(cuò)誤
這個(gè)錯(cuò)誤可能在B方案時(shí)就會(huì)出現(xiàn)，
解決方法：修改vobsub.c 230行將getline函數(shù)名稱改為mygetline

5）make完畢后拷貝目錄下的mplayer文件到arm9linux文件系統(tǒng)運(yùn)行就好了，我是拷貝在u盤里面運(yùn)行的
>/mnt # mplayer
>MPlayer 1.0pre7try2-3.3.2 (C) 2000-2005 MPlayer Team
>CPU: ARM
>Usage:?? mplayer [options] [url|path/]filename

6）播放mp3的問(wèn)題
A不帶參數(shù)運(yùn)行，如下
/mnt # mplayer 1.mp3
MPlayer 1.0pre7try2-3.3.2 (C) 2000-2005 MPlayer Team
CPU: ARM
Failed to open /dev/rtc: No such file or directory (it should be readable by the user.)
Playing 1.mp3.
Audio file detected.
Clip inf
Title: 高達(dá)一年戰(zhàn)爭(zhēng)秘聞錄
Artist: Taja
Album:
Year:
Comment:
Genre: Other
==========================================================================
Requested audio codec family [mp3] (afm=mp3lib) not available.
Enable it at compilation.
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDI 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (rati 16000->176400)
Selected audio codec: [ffmp3] afm:ffmpeg (FFmpeg MPEG layer-3 audio decoder)
==========================================================================
Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or directory
A [null] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
Vide no video
Starting playback...
[Mixer] No hardware mixing, inserting volume filter.???????????????????????????
A:?? 0.3 (00.2) 47.4%??????????????????????????????????????????????????????????
A:?? 0.8 (00.8) 55.9%??????????????????????????????????????????????????????????
A:?? 1.2 (01.1) 57.2%??????????????????????????????????????????????????????????
No bind found for key l

打不開，因?yàn)闆](méi)有安裝mp3lib庫(kù)

B加參數(shù)mad
/mnt # mplayer -ac mad 1.mp3
MPlayer 1.0pre7try2-3.3.2 (C) 2000-2005 MPlayer Team
CPU: ARM
Failed to open /dev/rtc: No such file or directory (it should be readable by the user.)
Playing 1.mp3.
Audio file detected.
Clip inf
Title: 高達(dá)一年戰(zhàn)爭(zhēng)秘聞錄
Artist: Taja
Album:
Year:
Comment:
Genre: Other
==========================================================================
Forced audio codec: mad
Opening audio decoder: [libmad] libmad mpeg audio decoder
AUDI 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (rati 16000->176400)
Selected audio codec: [mad] afm:libmad (libMAD MPEG layer 1-2-3)
==========================================================================
Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or directory
A [null] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
Vide no video
Starting playback...
A:?? 3.9 (03.8) 46.9%

看似在播放了，但是完全沒(méi)有聲音
仔細(xì)看輸出，有個(gè)錯(cuò)誤[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or directory

奇怪，我記得dsp應(yīng)該在sound下啊
既然它要找/dev/dsp，我做個(gè)鏈接好了
前天剛學(xué)過(guò)ln命令，現(xiàn)學(xué)現(xiàn)賣
ln -s /dev/sound/dsp /dev/dsp

再運(yùn)行看看
/mnt # mplayer -ac mad 1.mp3
MPlayer 1.0pre7try2-3.3.2 (C) 2000-2005 MPlayer Team
CPU: ARM
Failed to open /dev/rtc: No such file or directory (it should be readable by the user.)
Playing 1.mp3.
Audio file detected.
Clip inf
Title: 高達(dá)一年戰(zhàn)爭(zhēng)秘聞錄
Artist: Taja
Album:
Year:
Comment:
Genre: Other
==========================================================================
Forced audio codec: mad
Opening audio decoder: [libmad] libmad mpeg audio decoder
AUDI 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (rs3c2410-uda1341-superlp: audio_set_dsp_speed:44100 prescaler:66
ati 16000->176s3c2410-uda1341-superlp: audio_set_dsp_speed:44100 prescaler:66
400)
Selected audio codec: [mad] afm:libmad (libMAD MPEG layer 1-2-3)
==========================================================================
Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
A [oss] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
Vide no video
Starting playback...

MPlayer interrupted by signal 8 in module: play_audio
- MPlayer crashed by bad usage of CPU/FPU/RAM.
Recompile MPlayer with --enable-debug and make a 'gdb' backtrace and
disassembly. Details in DOCS/HTML/en/bugreports_what.html#bugreports_crash.
- MPlayer crashed. This shouldn't happen.
It can be a bug in the MPlayer code _or_ in your drivers _or_ in your
gcc version. If you think it's MPlayer's fault, please read
DOCS/HTML/en/bugreports.html and follow the instructions there. We can't and
won't help unless you provide this information when reporting a possible bug.

還是有錯(cuò)誤，但AO的錯(cuò)誤解決了，我目前僅做到這一步，尚未解決聲音問(wèn)題

6）播放視頻
我嘗試了avi mpg vcd的dat文件，都可以播放，速度有點(diǎn)滿，還得禁掉sound，2410也就這樣吧，放視頻還得DSP

mplayer 13.mpg -nosound -fs
fs是中央顯示

還有個(gè)錯(cuò)誤
Failed to open /dev/rtc: No such file or directory (it should be readable by the user.)
RTC的錯(cuò)誤？我找不到這個(gè)設(shè)備
暫時(shí)就這么多吧，聲音問(wèn)題繼續(xù)研究中。。。。。。。。。。。。。。。。
最后轉(zhuǎn)一段解決聲音問(wèn)題的方法，我按照如上做了，可惜還是沒(méi)解決

2．開始調(diào)試???
??????? 編譯出來(lái)的代碼能正常的在FS2410上跑嗎？心中還是有許多疑問(wèn)。給板子上電，然后用自己編寫的一個(gè)網(wǎng)絡(luò)傳輸工具將代碼傳到板子的ramdisk，接著 再傳上一個(gè)10M左右的視頻，好了，先不帶參數(shù)運(yùn)行mplayer，不錯(cuò)，中文的幫助信息彈出來(lái)了，說(shuō)明程序基本編譯對(duì)了，這時(shí)輸入命令?? ./mplayer???? matrix.mpg?? ,?? 眼睛直盯著屏幕，期待著畫面的出現(xiàn)，可惜，在出現(xiàn)了一些視頻剪輯的反饋信息后，程序再也不動(dòng)了，沒(méi)辦法，按CTRL+C結(jié)束程序，然后就提示出現(xiàn)段錯(cuò)誤。 以前聽說(shuō)有l(wèi)inux嵌入式的愛(ài)好者移植時(shí)也出現(xiàn)這樣的錯(cuò)誤，但是如果不播放聲音時(shí)，圖像可以出現(xiàn)，于是輸入命令?? ./mplayer???? －nosound???? matrix.mpg，這時(shí)畫面出來(lái)了，這個(gè)320x240大小的從網(wǎng)上下載的視頻，播放起來(lái)相當(dāng)流暢，好像比平時(shí)看的影碟機(jī)解碼速度還快，那當(dāng)然了，畢 竟是320x240大小，又沒(méi)聲音解碼的。??
???
聲音這塊不解決，當(dāng)然是不能說(shuō)移植成功的，因?yàn)閙player還支持那么多格式的音頻解碼。但是問(wèn)題究竟出在哪里呢？用排除法吧！找一個(gè)未經(jīng)任何音頻壓縮 的WAV音頻文件，其時(shí)就是PCM文件，上傳到ramdisk，然后用mplayer播放，還是出現(xiàn)一樣的問(wèn)題，程序死了。好了，這就說(shuō)明問(wèn)題并非出現(xiàn)在 音頻解碼部分，極有可能出現(xiàn)在音頻流的播放部分?，F(xiàn)在市面上大多數(shù)的嵌入式開發(fā)板的音頻驅(qū)動(dòng)是oss規(guī)范的驅(qū)動(dòng)，以前自己做過(guò)oss的編程，對(duì)這塊還是比 較熟悉。于是開始查看mpalyer,c源文件，看看它是如何實(shí)現(xiàn)音頻流播放的，??
???
在音頻播放部分它使用到了libao2庫(kù)的音頻播放/控制模塊，通過(guò)進(jìn)一步查看ao_oss.c源代碼進(jìn)一步獲知mplayer是如何與音頻的linux 驅(qū)動(dòng)工作的。這一步弄清楚后，重新編譯mplayer，打開debug選項(xiàng)，打開調(diào)試字符串輸出，并在音頻播放處設(shè)置多處斷點(diǎn)，并加上printf語(yǔ)句輸 出一些變量?jī)?nèi)容，最終發(fā)現(xiàn)在調(diào)用ao_oss.c的play（）函數(shù)時(shí)出現(xiàn)除零出錯(cuò)，??
???
這個(gè)問(wèn)題產(chǎn)生的根源最終追溯到音頻的驅(qū)動(dòng)部分?，F(xiàn)在大部分的嵌入式板子都使用菲利普uda1341音頻芯片，因而也都使用了相同一個(gè)音頻驅(qū)動(dòng)，即MIZI 公司擁有版權(quán)的linux?? uda1341音頻驅(qū)動(dòng)，這個(gè)驅(qū)動(dòng)基本上符合了oss的規(guī)范，但是當(dāng)使用到多段DMA音頻數(shù)據(jù)傳輸時(shí)，出現(xiàn)了一個(gè)問(wèn)題，即DMA緩沖的建立發(fā)生在第一次調(diào) 用write（）函數(shù)將音頻數(shù)據(jù)傳送到設(shè)備描述符的時(shí)候，然而oss驅(qū)動(dòng)的調(diào)用者通常要在打開音頻設(shè)備描述時(shí)候，就期望獲取DMA緩沖的信息，然而因?yàn)榫?沖尚未建立，因而返回緩沖大小為0這個(gè)結(jié)果。??
???
解決的辦法是在音頻驅(qū)動(dòng)源碼的smdk2410_audio_open（）函數(shù)體，加上如下一段代碼，??
???
if?? (!output_stream?? .buffers?? &&?? audio_setup_buf(&output_stream))??
????????????????????????????????????????????? return?? -ENOMEM;??
????? 添加的位置具體見(jiàn)以下代碼的粗體部分：??
????????????? static?? int?? smdk2410_audio_open(struct?? inode?? *inode,?? struct?? file?? *file)??
????? {??
??????????????????? int?? cold?? =?? !audio_active;??
??????????????????????????? DPRINTK("audio_open ");??
??????????????????????????? if?? ((file->f_flags?? &?? O_ACCMODE)?? ==?? O_RDONLY)?? {??
????????????????????????????????? if?? (audio_rd_refcount?? ||?? audio_wr_refcount)??
??????????????????????????????????????????????? return?? -EBUSY;??
????????????????????????????????? audio_rd_refcount++;??
??????????????????? }?? else?? if?? ((file->f_flags?? &?? O_ACCMODE)?? ==?? O_WRONLY)?? {??
????????????????????????????????? if?? (audio_wr_refcount)??
??????????????????????????????????????????????? return?? -EBUSY;??
????????????????????????????????? audio_wr_refcount++;??
??????????????????? }?? else?? if?? ((file->f_flags?? &?? O_ACCMODE)?? ==?? O_RDWR)?? {??
????????????????????????????????? if?? (audio_rd_refcount?? ||?? audio_wr_refcount)??
??????????????????????????????????????????????? return?? -EBUSY;??
????????????????????????????????? audio_rd_refcount++;??
????????????????????????????????? audio_wr_refcount++;??
??????????????????? }?? else??
????????????????????????????????? return?? -EINVAL;??
????????????????????????? if?? (cold)?? {??
????????????????????????????????? audio_rate?? =?? AUDIO_RATE_DEFAULT;??
????????????????????????????????? audio_channels?? =?? AUDIO_CHANNELS_DEFAULT;??
????????????????????????????????? audio_fragsize?? =?? AUDIO_FRAGSIZE_DEFAULT;??
????????????????????????????????? audio_nbfrags?? =?? AUDIO_NBFRAGS_DEFAULT;??
????????????????????????????????? if?? ((file->f_mode?? &?? FMODE_WRITE)){??
????????????????????????????????????????????????????????????? init_s3c2410_iis_bus_tx();??
????????????????????????????????????????????????????????????? audio_clear_buf(&output_stream);??
??????????????????????????????????? //?? 加上以下這行代碼??
??????????????????????????????????????? if?? (!output_stream?? .buffers?? &&?? audio_setup_buf(&output_stream))??
????????????????????????????????????????????? return?? -ENOMEM;??
????????????????????????????????? }??
????????????????????????????????? if?? ((file->f_mode?? &?? FMODE_READ)){??
????????????????????????????????????????????????????????????? init_s3c2410_iis_bus_rx();??
????????????????????????????????????????????????????????????? audio_clear_buf(&input_stream);??
????????????????????????????????? }??
??????????????? }??
??????????????? MOD_INC_USE_COUNT;??
?????????????? return?? 0;??
??? }??
??? 改完驅(qū)動(dòng)后，重新編譯內(nèi)核。

=====================================================

更新
解決Failed to open /dev/rtc: No such file or directory (it should be readable by the user.)問(wèn)題
在configure時(shí)添加 --disable-rtc