build - 升级ffmpeg时处理ffmpeg库接口(interface)变化

Question

我们目前正在尝试升级我们的程序使用的 ffmpeg 版本。跳跃很大，因为我们目前使用的是 ffmpeg 0.8，最新版本是 1.2。

在这些测试中，我使用的是(让我说)我发现的令人惊叹的软件包 here .

首先，我尝试下载并构建 ffmpeg 1.2，当然，我收到了很多关于已弃用或不再存在的函数和变量的警告和错误。

为了顺利过渡，我尝试针对 ffmpeg 1.0 进行构建，这是相对于 0.8 最接近的更高版本。我收到了下面列出的警告和错误列表。

我的问题如下:是否存在任何指南来帮助进行这些过渡，以在新版本中转换旧的 ffmpeg 范例/函数调用？我没有写，我不想逐行分析，如果可以将旧函数调用一对一转换为新函数调用，对于变量也是如此，我会非常高兴。

这是警告和错误的列表(我已清理它，因此每个错误/警告只有一个条目)

warning: 'AVStream* av_new_stream(AVFormatContext*, int)' is deprecated (declared at /ffmpeg/include/libavformat/avformat.h:1646) [-Wdeprecated-declarations]

warning: 'int avcodec_open(AVCodecContext*, AVCodec*)' is deprecated (declared at /ffmpeg/include/libavcodec/avcodec.h:3569) [-Wdeprecated-declarations]
error: 'avcodec_init' was not declared in this scope
warning: 'int avcodec_encode_video(AVCodecContext*, uint8_t*, int, const AVFrame*)' is deprecated (declared at /ffmpeg/include/libavcodec/avcodec.h:4272) [-Wdeprecated-declarations]

warning: 'AVCodecContext* avcodec_alloc_context()' is deprecated (declared at /ffmpeg/include/libavcodec/avcodec.h:3423) [-Wdeprecated-declarations]

warning: 'int avcodec_decode_audio3(AVCodecContext*, int16_t*, int*, AVPacket*)' is deprecated (declared at /ffmpeg/include/libavcodec/avcodec.h:3852) [-Wdeprecated-declarations]

warning: 'void av_close_input_file(AVFormatContext*)' is deprecated (declared at /ffmpeg/include/libavformat/avformat.h:1622) [-Wdeprecated-declarations]
error: 'av_open_input_file' was not declared in this scope
warning: 'int av_find_stream_info(AVFormatContext*)' is deprecated (declared at /ffmpeg/include/libavformat/avformat.h:1446) [-Wdeprecated-declarations]
error: 'av_set_parameters' was not declared in this scope

error: 'AVFormatContext' has no member named 'file_size'

error: 'URL_WRONLY' was not declared in this scope

error: 'url_fopen' was not declared in this scope
error: 'url_fclose' was not declared in this scope

error: 'SAMPLE_FMT_U8' was not declared in this scope
error: 'SAMPLE_FMT_S16' was not declared in this scope
error: 'SAMPLE_FMT_S32' was not declared in this scope
error: 'SAMPLE_FMT_FLT' was not declared in this scope

error: 'FF_I_TYPE' was not declared in this scope

编辑:

我正在看这些...
http://ffmpeg.org/doxygen/0.8/deprecated.html
http://ffmpeg.org/doxygen/0.9/deprecated.html
http://ffmpeg.org/doxygen/1.0/deprecated.html
http://ffmpeg.org/doxygen/1.1/deprecated.html
http://ffmpeg.org/doxygen/1.2/deprecated.html
http://ffmpeg.org/doxygen/trunk/deprecated.html

Answer 1

看看here .

URL_WRONLY -> AVIO_FLAG_WRITE
url_fopen -> avio_open
url_fclose -> avio_close

希望以上内容足以帮助您入门。

<小时/>

如果链接失效，以下是全文:

I found some resources about how to port old code (here, here and here), but since it wasn't what I needed I decided to write my own version. So, here we go.

url_open()

This function has been changed to avio_open. There is also url_close which is renamed to avio_close. This information I found here.

av_new_stream()

This function is still supported as of FFMPEG 1.0.1 but it is marked as deprecated. It will be replaced with avformat_new_stream(). Suppose that the old code was:

AVStream *st = av_new_stream(oc, i);

the modified code should be:

AVStream *st = avformat_new_stream(oc, NULL);
st->id = i

Be careful to check first that st isn't NULL!

dump_format()

This function was renamed to av_dump_format().

av_write_header()

Replaced with avformat_write_header() that accepts two arguments instead of one. Pass NULL as the second argument to get identical behavior to the old function.

av_codec_open()

This one is replaced with av_codec_open2(). The replacement function accepts three arguments instead of two, but put NULL as a third argument to get the same behavior as the old function.

avcodec_encode_audio()

Replaced with avcodec_encode_audio2().

av_set_parameters()

I couldn't fine the replacement for this one. First, I've found that this function doesn't have replacement. But it was when it was still available in FFMPEG, even though deprecated. Then, they removed it, and thus it has to have replacement. In certain places I found that they only disabled it, on others that its parameters have to be passed to avformat_write_header. In the end, I gave up because I didn't need working version of that part of the code for now. Since in my case avformat_alloc_context() is called and then av_set_parameters(), last what I looked at was to call avformat_alloc_output_context2() instead of avformat_alloc_context(). But the change is not trivial so I skipped it.

SampleFormat

This enum has been renamed AVSampleFormat.

URL_WRONLY

This constant has been replaced with AVIO_FLAG_WRITE.

SAMPLE_FMT_U8, SAMPLE_FMT_S16, SAMPLE_FMT_S32, etc.

Those are prefixed now with AV_, so use AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S16, etc.