[FFmpeg-devel,v4,5/7] lavd: add new API for iterating input and output devices

This also adds an avpriv function to register devices in
libavformat
---
 Makefile                 |   3 +-
 configure                |  27 +++++--
 libavdevice/.gitignore   |   2 +
 libavdevice/alldevices.c | 181 ++++++++++++++++++++++++++++++++++++-----------
 libavdevice/avdevice.c   |  46 ------------
 libavdevice/avdevice.h   |  28 ++++++++
 libavdevice/version.h    |   4 ++
 libavformat/allformats.c |  45 +++++++++++-
 libavformat/format.c     |   8 +++
 libavformat/internal.h   |   7 ++
 10 files changed, 255 insertions(+), 96 deletions(-)
 create mode 100644 libavdevice/.gitignore

On Sat, Feb 3, 2018 at 2:44 AM, Josh de Kock <josh@itanimul.li> wrote:
> This also adds an avpriv function to register devices in
> libavformat
> ---
>  Makefile                 |   3 +-
>  configure                |  27 +++++--
>  libavdevice/.gitignore   |   2 +
>  libavdevice/alldevices.c | 181 ++++++++++++++++++++++++++++++++++++-----------
>  libavdevice/avdevice.c   |  46 ------------
>  libavdevice/avdevice.h   |  28 ++++++++
>  libavdevice/version.h    |   4 ++
>  libavformat/allformats.c |  45 +++++++++++-
>  libavformat/format.c     |   8 +++
>  libavformat/internal.h   |   7 ++
>  10 files changed, 255 insertions(+), 96 deletions(-)
>  create mode 100644 libavdevice/.gitignore
>
> diff --git a/Makefile b/Makefile
> index 0cd0a1d..bb93b69 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -144,7 +144,8 @@ distclean:: clean
>                 version.h libavutil/ffversion.h libavcodec/codec_names.h \
>                 libavcodec/bsf_list.c libavformat/protocol_list.c \
>                 libavcodec/codec_list.c libavcodec/parser_list.c \
> -               libavformat/muxer_list.c libavformat/demuxer_list.c
> +               libavformat/muxer_list.c libavformat/demuxer_list.c \
> +               libavdevice/indev_list.c libavdevice/outdev_list.c
>  ifeq ($(SRC_LINK),src)
>         $(RM) src
>  endif
> diff --git a/configure b/configure
> index d6d7980..040b848 100755
> --- a/configure
> +++ b/configure
> @@ -568,6 +568,12 @@ add_suffix(){
>      for v; do echo ${v}${suffix}; done
>  }
>
> +remove_suffix(){
> +    suffix=$1
> +    shift
> +    for v; do echo ${v%$suffix}; done
> +}
> +
>  set_all(){
>      value=$1
>      shift
> @@ -3523,17 +3529,18 @@ find_things(){
>      sed -n "s/^[^#]*$pattern.*([^,]*, *\([^,]*\)\(,.*\)*).*/\1_$thing/p" "$file"
>  }
>
> -OUTDEV_LIST=$(find_things   outdev   OUTDEV   libavdevice/alldevices.c)
> -INDEV_LIST=$(find_things    indev    _IN      libavdevice/alldevices.c)
>  FILTER_LIST=$(find_things   filter   FILTER   libavfilter/allfilters.c)
>
>  find_things_extern(){
>      thing=$1
>      pattern=$2
>      file=$source_path/$3
> -    sed -n "s/^[^#]*extern.*$pattern *ff_\([^ ]*\)_$thing;/\1_$thing/p" "$file"
> +    out=${4:-$thing}
> +    sed -n "s/^[^#]*extern.*$pattern *ff_\([^ ]*\)_$thing;/\1_$out/p" "$file"
>  }
>
> +OUTDEV_LIST=$(find_things_extern muxer AVOutputFormat libavdevice/alldevices.c outdev)
> +INDEV_LIST=$(find_things_extern demuxer AVInputFormat libavdevice/alldevices.c indev)
>  MUXER_LIST=$(find_things_extern muxer AVOutputFormat libavformat/allformats.c)
>  DEMUXER_LIST=$(find_things_extern demuxer AVInputFormat libavformat/allformats.c)
>  ENCODER_LIST=$(find_things_extern encoder AVCodec libavcodec/allcodecs.c)
> @@ -7025,7 +7032,17 @@ print_enabled_components(){
>      shift 3
>      echo "static const $struct_name * const $name[] = {" > $TMPH
>      for c in $*; do
> -        enabled $c && printf "    &ff_%s,\n" $c >> $TMPH
> +        if enabled $c; then
> +            case $name in
> +                indev_list)
> +                    c=$(add_suffix _demuxer $(remove_suffix _indev $c))
> +                ;;
> +                outdev_list)
> +                    c=$(add_suffix _muxer $(remove_suffix _outdev $c))
> +                ;;
> +            esac
> +            printf "    &ff_%s,\n" $c >> $TMPH
> +        fi
>      done
>      echo "    NULL };" >> $TMPH
>      cp_if_changed $TMPH $file
> @@ -7034,6 +7051,8 @@ print_enabled_components(){
>  print_enabled_components libavcodec/codec_list.c AVCodec codec_list $CODEC_LIST
>  print_enabled_components libavcodec/parser_list.c AVCodecParser parser_list $PARSER_LIST
>  print_enabled_components libavcodec/bsf_list.c AVBitStreamFilter bitstream_filters $BSF_LIST
> +print_enabled_components libavdevice/indev_list.c AVInputFormat indev_list $INDEV_LIST
> +print_enabled_components libavdevice/outdev_list.c AVOutputFormat outdev_list $OUTDEV_LIST
>  print_enabled_components libavformat/demuxer_list.c AVInputFormat demuxer_list $DEMUXER_LIST
>  print_enabled_components libavformat/muxer_list.c AVOutputFormat muxer_list $MUXER_LIST
>  print_enabled_components libavformat/protocol_list.c URLProtocol url_protocols $PROTOCOL_LIST
> diff --git a/libavdevice/.gitignore b/libavdevice/.gitignore
> new file mode 100644
> index 0000000..08ac3eb
> --- /dev/null
> +++ b/libavdevice/.gitignore
> @@ -0,0 +1,2 @@
> +/indev_list.c
> +/outdev_list.c
> diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
> index b767b6a..8b58aa1 100644
> --- a/libavdevice/alldevices.c
> +++ b/libavdevice/alldevices.c
> @@ -22,57 +22,152 @@
>  #include "libavutil/thread.h"
>  #include "avdevice.h"
>
> -#define REGISTER_OUTDEV(X, x)                                           \
> -    {                                                                   \
> -        extern AVOutputFormat ff_##x##_muxer;                           \
> -        if (CONFIG_##X##_OUTDEV)                                        \
> -            av_register_output_format(&ff_##x##_muxer);                 \
> +#if FF_API_NEXT
> +#include "libavformat/internal.h"
> +#endif
> +
> +/* devices */
> +extern AVInputFormat  ff_alsa_demuxer;
> +extern AVOutputFormat ff_alsa_muxer;
> +extern AVInputFormat  ff_avfoundation_demuxer;
> +extern AVInputFormat  ff_bktr_demuxer;
> +extern AVOutputFormat ff_caca_muxer;
> +extern AVInputFormat  ff_decklink_demuxer;
> +extern AVOutputFormat ff_decklink_muxer;
> +extern AVInputFormat  ff_libndi_newtek_demuxer;
> +extern AVOutputFormat ff_libndi_newtek_muxer;
> +extern AVInputFormat  ff_dshow_demuxer;
> +extern AVInputFormat  ff_fbdev_demuxer;
> +extern AVOutputFormat ff_fbdev_muxer;
> +extern AVInputFormat  ff_gdigrab_demuxer;
> +extern AVInputFormat  ff_iec61883_demuxer;
> +extern AVInputFormat  ff_jack_demuxer;
> +extern AVInputFormat  ff_kmsgrab_demuxer;
> +extern AVInputFormat  ff_lavfi_demuxer;
> +extern AVInputFormat  ff_openal_demuxer;
> +extern AVOutputFormat ff_opengl_muxer;
> +extern AVInputFormat  ff_oss_demuxer;
> +extern AVOutputFormat ff_oss_muxer;
> +extern AVInputFormat  ff_pulse_demuxer;
> +extern AVOutputFormat ff_pulse_muxer;
> +extern AVOutputFormat ff_sdl2_muxer;
> +extern AVInputFormat  ff_sndio_demuxer;
> +extern AVOutputFormat ff_sndio_muxer;
> +extern AVInputFormat  ff_v4l2_demuxer;
> +extern AVOutputFormat ff_v4l2_muxer;
> +extern AVInputFormat  ff_vfwcap_demuxer;
> +extern AVInputFormat  ff_xcbgrab_demuxer;
> +extern AVOutputFormat ff_xv_muxer;
> +
> +/* external libraries */
> +extern AVInputFormat  ff_libcdio_demuxer;
> +extern AVInputFormat  ff_libdc1394_demuxer;
> +
> +#include "libavdevice/outdev_list.c"
> +#include "libavdevice/indev_list.c"
> +
> +const AVOutputFormat *av_outdev_iterate(void **opaque)
> +{
> +    uintptr_t i = (uintptr_t)*opaque;
> +    const AVOutputFormat *f = outdev_list[i];
> +
> +    if (f)
> +        *opaque = (void*)(i + 1);
> +    return f;
> +}
> +
> +const AVInputFormat *av_indev_iterate(void **opaque)
> +{
> +    uintptr_t i = (uintptr_t)*opaque;
> +    const AVInputFormat *f = indev_list[i];
> +
> +    if (f)
> +        *opaque = (void*)(i + 1);
> +    return f;
> +}
> +
> +#if FF_API_NEXT
> +FF_DISABLE_DEPRECATION_WARNINGS
> +static AVOnce av_device_next_init = AV_ONCE_INIT;
> +
> +static void av_device_init_next(void)
> +{
> +    AVOutputFormat *prevout = NULL, *out;
> +    AVInputFormat *previn = NULL, *in;
> +    void *i = 0;
> +
> +    while ((out = (AVOutputFormat*)av_outdev_iterate(&i))) {
> +        if (prevout)
> +            prevout->next = out;
> +        prevout = out;
>      }
>
> -#define REGISTER_INDEV(X, x)                                            \
> -    {                                                                   \
> -        extern AVInputFormat ff_##x##_demuxer;                          \
> -        if (CONFIG_##X##_INDEV)                                         \
> -            av_register_input_format(&ff_##x##_demuxer);                \
> +    i = 0;
> +    while ((in = (AVInputFormat*)av_indev_iterate(&i))) {
> +        if (previn)
> +            previn->next = in;
> +        previn = in;
>      }
>
> -#define REGISTER_INOUTDEV(X, x) REGISTER_OUTDEV(X, x); REGISTER_INDEV(X, x)
> +    avpriv_register_devices(outdev_list, indev_list);
> +}
>
> -static void register_all(void)
> +void avdevice_register_all(void)
>  {
> -    /* devices */
> -    REGISTER_INOUTDEV(ALSA,             alsa);
> -    REGISTER_INDEV   (AVFOUNDATION,     avfoundation);
> -    REGISTER_INDEV   (BKTR,             bktr);
> -    REGISTER_OUTDEV  (CACA,             caca);
> -    REGISTER_INOUTDEV(DECKLINK,         decklink);
> -    REGISTER_INOUTDEV(LIBNDI_NEWTEK,    libndi_newtek);
> -    REGISTER_INDEV   (DSHOW,            dshow);
> -    REGISTER_INOUTDEV(FBDEV,            fbdev);
> -    REGISTER_INDEV   (GDIGRAB,          gdigrab);
> -    REGISTER_INDEV   (IEC61883,         iec61883);
> -    REGISTER_INDEV   (JACK,             jack);
> -    REGISTER_INDEV   (KMSGRAB,          kmsgrab);
> -    REGISTER_INDEV   (LAVFI,            lavfi);
> -    REGISTER_INDEV   (OPENAL,           openal);
> -    REGISTER_OUTDEV  (OPENGL,           opengl);
> -    REGISTER_INOUTDEV(OSS,              oss);
> -    REGISTER_INOUTDEV(PULSE,            pulse);
> -    REGISTER_OUTDEV  (SDL2,             sdl2);
> -    REGISTER_INOUTDEV(SNDIO,            sndio);
> -    REGISTER_INOUTDEV(V4L2,             v4l2);
> -    REGISTER_INDEV   (VFWCAP,           vfwcap);
> -    REGISTER_INDEV   (XCBGRAB,          xcbgrab);
> -    REGISTER_OUTDEV  (XV,               xv);
> -
> -    /* external libraries */
> -    REGISTER_INDEV   (LIBCDIO,          libcdio);
> -    REGISTER_INDEV   (LIBDC1394,        libdc1394);
> +    ff_thread_once(&av_device_next_init, av_device_init_next);
>  }
>
> -void avdevice_register_all(void)
> +static void *device_next(void *prev, int output,
> +                         AVClassCategory c1, AVClassCategory c2)
> +{
> +    const AVClass *pc;
> +    AVClassCategory category = AV_CLASS_CATEGORY_NA;
> +
> +    ff_thread_once(&av_device_next_init, av_device_init_next);
> +
> +    if (!prev && !(prev = (output ? (void*)outdev_list[0] : (void*)indev_list[0])))
> +        return NULL;
> +
> +    do {
> +        if (output) {
> +            if (!(prev = ((AVOutputFormat *)prev)->next))
> +                break;
> +            pc = ((AVOutputFormat *)prev)->priv_class;
> +        } else {
> +            if (!(prev = ((AVInputFormat *)prev)->next))
> +                break;
> +            pc = ((AVInputFormat *)prev)->priv_class;
> +        }
> +        if (!pc)
> +            continue;
> +        category = pc->category;
> +    } while (category != c1 && category != c2);
> +    return prev;
> +}
> +
> +AVInputFormat *av_input_audio_device_next(AVInputFormat  *d)
> +{
> +    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
> +                       AV_CLASS_CATEGORY_DEVICE_INPUT);
> +}
> +
> +AVInputFormat *av_input_video_device_next(AVInputFormat  *d)
> +{
> +    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
> +                       AV_CLASS_CATEGORY_DEVICE_INPUT);
> +}
> +
> +AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d)
>  {
> -    static AVOnce control = AV_ONCE_INIT;
> +    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
> +                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
> +}
>
> -    ff_thread_once(&control, register_all);
> +AVOutputFormat *av_output_video_device_next(AVOutputFormat *d)
> +{
> +    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
> +                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
>  }
> +FF_DISABLE_DEPRECATION_WARNINGS
> +#endif
> +
> diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
> index 72e1b67..a42d349 100644
> --- a/libavdevice/avdevice.c
> +++ b/libavdevice/avdevice.c
> @@ -78,52 +78,6 @@ const char * avdevice_license(void)
>      return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
>  }
>
> -static void *device_next(void *prev, int output,
> -                         AVClassCategory c1, AVClassCategory c2)
> -{
> -    const AVClass *pc;
> -    AVClassCategory category = AV_CLASS_CATEGORY_NA;
> -    do {
> -        if (output) {
> -            if (!(prev = av_oformat_next(prev)))
> -                break;
> -            pc = ((AVOutputFormat *)prev)->priv_class;
> -        } else {
> -            if (!(prev = av_iformat_next(prev)))
> -                break;
> -            pc = ((AVInputFormat *)prev)->priv_class;
> -        }
> -        if (!pc)
> -            continue;
> -        category = pc->category;
> -    } while (category != c1 && category != c2);
> -    return prev;
> -}
> -
> -AVInputFormat *av_input_audio_device_next(AVInputFormat  *d)
> -{
> -    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
> -                       AV_CLASS_CATEGORY_DEVICE_INPUT);
> -}
> -
> -AVInputFormat *av_input_video_device_next(AVInputFormat  *d)
> -{
> -    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
> -                       AV_CLASS_CATEGORY_DEVICE_INPUT);
> -}
> -
> -AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d)
> -{
> -    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
> -                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
> -}
> -
> -AVOutputFormat *av_output_video_device_next(AVOutputFormat *d)
> -{
> -    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
> -                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
> -}
> -
>  int avdevice_app_to_dev_control_message(struct AVFormatContext *s, enum AVAppToDevMessageType type,
>                                          void *data, size_t data_size)
>  {
> diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h
> index ee94624..dd6ad93 100644
> --- a/libavdevice/avdevice.h
> +++ b/libavdevice/avdevice.h
> @@ -66,6 +66,29 @@ const char *avdevice_configuration(void);
>  const char *avdevice_license(void);
>
>  /**
> + * Iterate over all registered output devices.
> + *
> + * @param opaque a pointer where libavdevice will store the iteration state. Must
> + *               point to NULL to start the iteration.
> + *
> + * @return the next registered output device or NULL when the iteration is
> + *         finished
> + */
> +const AVOutputFormat *av_outdev_iterate(void **opaque);
> +
> +/**
> + * Iterate over all registered input devices.
> + *
> + * @param opaque a pointer where libavdevice will store the iteration state. Must
> + *               point to NULL to start the iteration.
> + *
> + * @return the next registered input device or NULL when the iteration is
> + *         finished
> + */
> +const AVInputFormat *av_indev_iterate(void **opaque);
> +
> +#if FF_API_NEXT
> +/**
>   * Initialize libavdevice and register all the input and output devices.
>   */
>  void avdevice_register_all(void);
> @@ -77,6 +100,7 @@ void avdevice_register_all(void);
>   * if d is non-NULL, returns the next registered input audio/video device after d
>   * or NULL if d is the last one.
>   */
> +attribute_deprecated
>  AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
>
>  /**
> @@ -86,6 +110,7 @@ AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
>   * if d is non-NULL, returns the next registered input audio/video device after d
>   * or NULL if d is the last one.
>   */
> +attribute_deprecated
>  AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
>
>  /**
> @@ -95,6 +120,7 @@ AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
>   * if d is non-NULL, returns the next registered output audio/video device after d
>   * or NULL if d is the last one.
>   */
> +attribute_deprecated
>  AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
>
>  /**
> @@ -104,7 +130,9 @@ AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
>   * if d is non-NULL, returns the next registered output audio/video device after d
>   * or NULL if d is the last one.
>   */
> +attribute_deprecated
>  AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
> +#endif
>
>  typedef struct AVDeviceRect {
>      int x;      /**< x coordinate of top left corner */
> diff --git a/libavdevice/version.h b/libavdevice/version.h
> index 0d4477f..892c4f3 100644
> --- a/libavdevice/version.h
> +++ b/libavdevice/version.h
> @@ -47,4 +47,8 @@
>   * the public API and may change, break or disappear at any time.
>   */
>
> +#ifndef FF_API_NEXT
> +#define FF_API_NEXT              (LIBAVDEVICE_VERSION_MAJOR < 59)
> +#endif
> +
>  #endif /* AVDEVICE_VERSION_H */
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 09c4213..40f592b 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -20,11 +20,15 @@
>   */
>
>  #include "libavutil/thread.h"
> +#include "libavdevice/avdevice.h"
>  #include "avformat.h"
>  #include "rtp.h"
>  #include "rdt.h"
>  #include "url.h"
>  #include "version.h"
> +#if FF_API_NEXT
> +#include "internal.h"
> +#endif
>
>  /* (de)muxers */
>  extern AVOutputFormat ff_a64_muxer;
> @@ -480,6 +484,7 @@ const AVOutputFormat *av_muxer_iterate(void **opaque)
>  {
>      uintptr_t i = (uintptr_t)*opaque;
>      const AVOutputFormat *f = muxer_list[i];
> +
>      if (f)
>          *opaque = (void*)(i + 1);
>      return f;
> @@ -498,6 +503,9 @@ const AVInputFormat *av_demuxer_iterate(void **opaque){
>  FF_DISABLE_DEPRECATION_WARNINGS
>  static AVOnce av_format_next_init = AV_ONCE_INIT;
>
> +static const AVInputFormat * const *indev_list = NULL;
> +static const AVOutputFormat * const *outdev_list = NULL;
> +
>  static void av_format_init_next(void)
>  {
>      AVOutputFormat *prevout = NULL, *out;
> @@ -510,30 +518,63 @@ static void av_format_init_next(void)
>          prevout = out;
>      }
>
> +    if (outdev_list) {
> +        for (int j = 0; (out = (AVOutputFormat*)outdev_list[j]); j++) {
> +            if (prevout)
> +                prevout->next = out;
> +            prevout = out;
> +        }
> +    }
> +
>      i = 0;
>      while ((in = (AVInputFormat*)av_demuxer_iterate(&i))) {
>          if (previn)
>              previn->next = in;
>          previn = in;
>      }
> +
> +    if (indev_list) {
> +        for (int j = 0; (in = (AVInputFormat*)indev_list[j]); j++) {
> +            if (previn)
> +                previn->next = in;
> +            previn = in;
> +        }
> +    }
> +
> +}
> +
> +void avpriv_register_devices(const AVOutputFormat * const o[], const AVInputFormat * const i[])
> +{
> +    static AVMutex avpriv_register_devices_mutex = AV_MUTEX_INITIALIZER;
> +    ff_mutex_lock(&avpriv_register_devices_mutex);
> +    outdev_list = o;
> +    indev_list = i;
> +    av_format_init_next();
> +    ff_mutex_unlock(&avpriv_register_devices_mutex);
>  }
>
>  AVInputFormat *av_iformat_next(const AVInputFormat *f)
>  {
> +    void *i = 0;
>      ff_thread_once(&av_format_next_init, av_format_init_next);
> +
>      if (f)
>          return f->next;
>      else
> -        return demuxer_list[0];
> +    /* If there are no demuxers but input devices, then return the first input device.
> +     * This will still return null if both there are both no demuxers or input devices. */
> +        return demuxer_list[0] ? (AVInputFormat*)demuxer_list[0] : (AVInputFormat*)av_indev_iterate(&i);

This is dependency violation. libavformat should have no dependencies
with libavcodec.


>  }
>
>  AVOutputFormat *av_oformat_next(const AVOutputFormat *f)
>  {
> +    void *i = 0;
>      ff_thread_once(&av_format_next_init, av_format_init_next);
> +
>      if (f)
>          return f->next;
>      else
> -        return muxer_list[0];
> +        return muxer_list[0] ? (AVOutputFormat*)muxer_list[0] : (AVOutputFormat*)av_outdev_iterate(&i);

Same as above.


>  }
>
>  void av_register_all(void)
> diff --git a/libavformat/format.c b/libavformat/format.c
> index 608af1b..b8c5a90 100644
> --- a/libavformat/format.c
> +++ b/libavformat/format.c
> @@ -118,10 +118,18 @@ enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
>  AVInputFormat *av_find_input_format(const char *short_name)
>  {
>      AVInputFormat *fmt = NULL;
> +#if FF_API_NEXT
> +FF_DISABLE_DEPRECATION_WARNINGS
> +    while ((fmt = av_iformat_next(fmt)))
> +        if (av_match_name(short_name, fmt->name))
> +            return fmt;
> +FF_ENABLE_DEPRECATION_WARNINGS
> +#else
>      void *i = 0;
>      while ((fmt = av_demuxer_iterate(&i)))
>          if (av_match_name(short_name, fmt->name))
>              return fmt;
> +#endif

Sudden change when bumping version? Before bumping, it searches
demuxers+indevs, after bumping, it searches demuxers only?


>      return NULL;
>  }
>
> diff --git a/libavformat/internal.h b/libavformat/internal.h
> index 1e2a3e0..0d08576 100644
> --- a/libavformat/internal.h
> +++ b/libavformat/internal.h
> @@ -703,4 +703,11 @@ int ff_unlock_avformat(void);
>   */
>  void ff_format_set_url(AVFormatContext *s, char *url);
>
> +#if FF_API_NEXT
> +/**
> +  * Register devices in deprecated format linked list.
> +  */
> +void avpriv_register_devices(const AVOutputFormat * const o[], const AVInputFormat * const i[]);
> +#endif
> +
>  #endif /* AVFORMAT_INTERNAL_H */
> --
> 2.7.4
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel

On Tue, Feb 6, 2018 at 6:35 AM, Muhammad Faiz <mfcc64@gmail.com> wrote:
> On Sat, Feb 3, 2018 at 2:44 AM, Josh de Kock <josh@itanimul.li> wrote:
>> This also adds an avpriv function to register devices in
>> libavformat
>> ---
>>  Makefile                 |   3 +-
>>  configure                |  27 +++++--
>>  libavdevice/.gitignore   |   2 +
>>  libavdevice/alldevices.c | 181 ++++++++++++++++++++++++++++++++++++-----------
>>  libavdevice/avdevice.c   |  46 ------------
>>  libavdevice/avdevice.h   |  28 ++++++++
>>  libavdevice/version.h    |   4 ++
>>  libavformat/allformats.c |  45 +++++++++++-
>>  libavformat/format.c     |   8 +++
>>  libavformat/internal.h   |   7 ++
>>  10 files changed, 255 insertions(+), 96 deletions(-)
>>  create mode 100644 libavdevice/.gitignore
>>
>> diff --git a/Makefile b/Makefile
>> index 0cd0a1d..bb93b69 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -144,7 +144,8 @@ distclean:: clean
>>                 version.h libavutil/ffversion.h libavcodec/codec_names.h \
>>                 libavcodec/bsf_list.c libavformat/protocol_list.c \
>>                 libavcodec/codec_list.c libavcodec/parser_list.c \
>> -               libavformat/muxer_list.c libavformat/demuxer_list.c
>> +               libavformat/muxer_list.c libavformat/demuxer_list.c \
>> +               libavdevice/indev_list.c libavdevice/outdev_list.c
>>  ifeq ($(SRC_LINK),src)
>>         $(RM) src
>>  endif
>> diff --git a/configure b/configure
>> index d6d7980..040b848 100755
>> --- a/configure
>> +++ b/configure
>> @@ -568,6 +568,12 @@ add_suffix(){
>>      for v; do echo ${v}${suffix}; done
>>  }
>>
>> +remove_suffix(){
>> +    suffix=$1
>> +    shift
>> +    for v; do echo ${v%$suffix}; done
>> +}
>> +
>>  set_all(){
>>      value=$1
>>      shift
>> @@ -3523,17 +3529,18 @@ find_things(){
>>      sed -n "s/^[^#]*$pattern.*([^,]*, *\([^,]*\)\(,.*\)*).*/\1_$thing/p" "$file"
>>  }
>>
>> -OUTDEV_LIST=$(find_things   outdev   OUTDEV   libavdevice/alldevices.c)
>> -INDEV_LIST=$(find_things    indev    _IN      libavdevice/alldevices.c)
>>  FILTER_LIST=$(find_things   filter   FILTER   libavfilter/allfilters.c)
>>
>>  find_things_extern(){
>>      thing=$1
>>      pattern=$2
>>      file=$source_path/$3
>> -    sed -n "s/^[^#]*extern.*$pattern *ff_\([^ ]*\)_$thing;/\1_$thing/p" "$file"
>> +    out=${4:-$thing}
>> +    sed -n "s/^[^#]*extern.*$pattern *ff_\([^ ]*\)_$thing;/\1_$out/p" "$file"
>>  }
>>
>> +OUTDEV_LIST=$(find_things_extern muxer AVOutputFormat libavdevice/alldevices.c outdev)
>> +INDEV_LIST=$(find_things_extern demuxer AVInputFormat libavdevice/alldevices.c indev)
>>  MUXER_LIST=$(find_things_extern muxer AVOutputFormat libavformat/allformats.c)
>>  DEMUXER_LIST=$(find_things_extern demuxer AVInputFormat libavformat/allformats.c)
>>  ENCODER_LIST=$(find_things_extern encoder AVCodec libavcodec/allcodecs.c)
>> @@ -7025,7 +7032,17 @@ print_enabled_components(){
>>      shift 3
>>      echo "static const $struct_name * const $name[] = {" > $TMPH
>>      for c in $*; do
>> -        enabled $c && printf "    &ff_%s,\n" $c >> $TMPH
>> +        if enabled $c; then
>> +            case $name in
>> +                indev_list)
>> +                    c=$(add_suffix _demuxer $(remove_suffix _indev $c))
>> +                ;;
>> +                outdev_list)
>> +                    c=$(add_suffix _muxer $(remove_suffix _outdev $c))
>> +                ;;
>> +            esac
>> +            printf "    &ff_%s,\n" $c >> $TMPH
>> +        fi
>>      done
>>      echo "    NULL };" >> $TMPH
>>      cp_if_changed $TMPH $file
>> @@ -7034,6 +7051,8 @@ print_enabled_components(){
>>  print_enabled_components libavcodec/codec_list.c AVCodec codec_list $CODEC_LIST
>>  print_enabled_components libavcodec/parser_list.c AVCodecParser parser_list $PARSER_LIST
>>  print_enabled_components libavcodec/bsf_list.c AVBitStreamFilter bitstream_filters $BSF_LIST
>> +print_enabled_components libavdevice/indev_list.c AVInputFormat indev_list $INDEV_LIST
>> +print_enabled_components libavdevice/outdev_list.c AVOutputFormat outdev_list $OUTDEV_LIST
>>  print_enabled_components libavformat/demuxer_list.c AVInputFormat demuxer_list $DEMUXER_LIST
>>  print_enabled_components libavformat/muxer_list.c AVOutputFormat muxer_list $MUXER_LIST
>>  print_enabled_components libavformat/protocol_list.c URLProtocol url_protocols $PROTOCOL_LIST
>> diff --git a/libavdevice/.gitignore b/libavdevice/.gitignore
>> new file mode 100644
>> index 0000000..08ac3eb
>> --- /dev/null
>> +++ b/libavdevice/.gitignore
>> @@ -0,0 +1,2 @@
>> +/indev_list.c
>> +/outdev_list.c
>> diff --git a/libavdevice/alldevices.c b/libavdevice/alldevices.c
>> index b767b6a..8b58aa1 100644
>> --- a/libavdevice/alldevices.c
>> +++ b/libavdevice/alldevices.c
>> @@ -22,57 +22,152 @@
>>  #include "libavutil/thread.h"
>>  #include "avdevice.h"
>>
>> -#define REGISTER_OUTDEV(X, x)                                           \
>> -    {                                                                   \
>> -        extern AVOutputFormat ff_##x##_muxer;                           \
>> -        if (CONFIG_##X##_OUTDEV)                                        \
>> -            av_register_output_format(&ff_##x##_muxer);                 \
>> +#if FF_API_NEXT
>> +#include "libavformat/internal.h"
>> +#endif
>> +
>> +/* devices */
>> +extern AVInputFormat  ff_alsa_demuxer;
>> +extern AVOutputFormat ff_alsa_muxer;
>> +extern AVInputFormat  ff_avfoundation_demuxer;
>> +extern AVInputFormat  ff_bktr_demuxer;
>> +extern AVOutputFormat ff_caca_muxer;
>> +extern AVInputFormat  ff_decklink_demuxer;
>> +extern AVOutputFormat ff_decklink_muxer;
>> +extern AVInputFormat  ff_libndi_newtek_demuxer;
>> +extern AVOutputFormat ff_libndi_newtek_muxer;
>> +extern AVInputFormat  ff_dshow_demuxer;
>> +extern AVInputFormat  ff_fbdev_demuxer;
>> +extern AVOutputFormat ff_fbdev_muxer;
>> +extern AVInputFormat  ff_gdigrab_demuxer;
>> +extern AVInputFormat  ff_iec61883_demuxer;
>> +extern AVInputFormat  ff_jack_demuxer;
>> +extern AVInputFormat  ff_kmsgrab_demuxer;
>> +extern AVInputFormat  ff_lavfi_demuxer;
>> +extern AVInputFormat  ff_openal_demuxer;
>> +extern AVOutputFormat ff_opengl_muxer;
>> +extern AVInputFormat  ff_oss_demuxer;
>> +extern AVOutputFormat ff_oss_muxer;
>> +extern AVInputFormat  ff_pulse_demuxer;
>> +extern AVOutputFormat ff_pulse_muxer;
>> +extern AVOutputFormat ff_sdl2_muxer;
>> +extern AVInputFormat  ff_sndio_demuxer;
>> +extern AVOutputFormat ff_sndio_muxer;
>> +extern AVInputFormat  ff_v4l2_demuxer;
>> +extern AVOutputFormat ff_v4l2_muxer;
>> +extern AVInputFormat  ff_vfwcap_demuxer;
>> +extern AVInputFormat  ff_xcbgrab_demuxer;
>> +extern AVOutputFormat ff_xv_muxer;
>> +
>> +/* external libraries */
>> +extern AVInputFormat  ff_libcdio_demuxer;
>> +extern AVInputFormat  ff_libdc1394_demuxer;
>> +
>> +#include "libavdevice/outdev_list.c"
>> +#include "libavdevice/indev_list.c"
>> +
>> +const AVOutputFormat *av_outdev_iterate(void **opaque)
>> +{
>> +    uintptr_t i = (uintptr_t)*opaque;
>> +    const AVOutputFormat *f = outdev_list[i];
>> +
>> +    if (f)
>> +        *opaque = (void*)(i + 1);
>> +    return f;
>> +}
>> +
>> +const AVInputFormat *av_indev_iterate(void **opaque)
>> +{
>> +    uintptr_t i = (uintptr_t)*opaque;
>> +    const AVInputFormat *f = indev_list[i];
>> +
>> +    if (f)
>> +        *opaque = (void*)(i + 1);
>> +    return f;
>> +}
>> +
>> +#if FF_API_NEXT
>> +FF_DISABLE_DEPRECATION_WARNINGS
>> +static AVOnce av_device_next_init = AV_ONCE_INIT;
>> +
>> +static void av_device_init_next(void)
>> +{
>> +    AVOutputFormat *prevout = NULL, *out;
>> +    AVInputFormat *previn = NULL, *in;
>> +    void *i = 0;
>> +
>> +    while ((out = (AVOutputFormat*)av_outdev_iterate(&i))) {
>> +        if (prevout)
>> +            prevout->next = out;
>> +        prevout = out;
>>      }
>>
>> -#define REGISTER_INDEV(X, x)                                            \
>> -    {                                                                   \
>> -        extern AVInputFormat ff_##x##_demuxer;                          \
>> -        if (CONFIG_##X##_INDEV)                                         \
>> -            av_register_input_format(&ff_##x##_demuxer);                \
>> +    i = 0;
>> +    while ((in = (AVInputFormat*)av_indev_iterate(&i))) {
>> +        if (previn)
>> +            previn->next = in;
>> +        previn = in;
>>      }
>>
>> -#define REGISTER_INOUTDEV(X, x) REGISTER_OUTDEV(X, x); REGISTER_INDEV(X, x)
>> +    avpriv_register_devices(outdev_list, indev_list);
>> +}
>>
>> -static void register_all(void)
>> +void avdevice_register_all(void)
>>  {
>> -    /* devices */
>> -    REGISTER_INOUTDEV(ALSA,             alsa);
>> -    REGISTER_INDEV   (AVFOUNDATION,     avfoundation);
>> -    REGISTER_INDEV   (BKTR,             bktr);
>> -    REGISTER_OUTDEV  (CACA,             caca);
>> -    REGISTER_INOUTDEV(DECKLINK,         decklink);
>> -    REGISTER_INOUTDEV(LIBNDI_NEWTEK,    libndi_newtek);
>> -    REGISTER_INDEV   (DSHOW,            dshow);
>> -    REGISTER_INOUTDEV(FBDEV,            fbdev);
>> -    REGISTER_INDEV   (GDIGRAB,          gdigrab);
>> -    REGISTER_INDEV   (IEC61883,         iec61883);
>> -    REGISTER_INDEV   (JACK,             jack);
>> -    REGISTER_INDEV   (KMSGRAB,          kmsgrab);
>> -    REGISTER_INDEV   (LAVFI,            lavfi);
>> -    REGISTER_INDEV   (OPENAL,           openal);
>> -    REGISTER_OUTDEV  (OPENGL,           opengl);
>> -    REGISTER_INOUTDEV(OSS,              oss);
>> -    REGISTER_INOUTDEV(PULSE,            pulse);
>> -    REGISTER_OUTDEV  (SDL2,             sdl2);
>> -    REGISTER_INOUTDEV(SNDIO,            sndio);
>> -    REGISTER_INOUTDEV(V4L2,             v4l2);
>> -    REGISTER_INDEV   (VFWCAP,           vfwcap);
>> -    REGISTER_INDEV   (XCBGRAB,          xcbgrab);
>> -    REGISTER_OUTDEV  (XV,               xv);
>> -
>> -    /* external libraries */
>> -    REGISTER_INDEV   (LIBCDIO,          libcdio);
>> -    REGISTER_INDEV   (LIBDC1394,        libdc1394);
>> +    ff_thread_once(&av_device_next_init, av_device_init_next);
>>  }
>>
>> -void avdevice_register_all(void)
>> +static void *device_next(void *prev, int output,
>> +                         AVClassCategory c1, AVClassCategory c2)
>> +{
>> +    const AVClass *pc;
>> +    AVClassCategory category = AV_CLASS_CATEGORY_NA;
>> +
>> +    ff_thread_once(&av_device_next_init, av_device_init_next);
>> +
>> +    if (!prev && !(prev = (output ? (void*)outdev_list[0] : (void*)indev_list[0])))
>> +        return NULL;
>> +
>> +    do {
>> +        if (output) {
>> +            if (!(prev = ((AVOutputFormat *)prev)->next))
>> +                break;
>> +            pc = ((AVOutputFormat *)prev)->priv_class;
>> +        } else {
>> +            if (!(prev = ((AVInputFormat *)prev)->next))
>> +                break;
>> +            pc = ((AVInputFormat *)prev)->priv_class;
>> +        }
>> +        if (!pc)
>> +            continue;
>> +        category = pc->category;
>> +    } while (category != c1 && category != c2);
>> +    return prev;
>> +}
>> +
>> +AVInputFormat *av_input_audio_device_next(AVInputFormat  *d)
>> +{
>> +    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
>> +                       AV_CLASS_CATEGORY_DEVICE_INPUT);
>> +}
>> +
>> +AVInputFormat *av_input_video_device_next(AVInputFormat  *d)
>> +{
>> +    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
>> +                       AV_CLASS_CATEGORY_DEVICE_INPUT);
>> +}
>> +
>> +AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d)
>>  {
>> -    static AVOnce control = AV_ONCE_INIT;
>> +    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
>> +                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
>> +}
>>
>> -    ff_thread_once(&control, register_all);
>> +AVOutputFormat *av_output_video_device_next(AVOutputFormat *d)
>> +{
>> +    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
>> +                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
>>  }
>> +FF_DISABLE_DEPRECATION_WARNINGS
>> +#endif
>> +
>> diff --git a/libavdevice/avdevice.c b/libavdevice/avdevice.c
>> index 72e1b67..a42d349 100644
>> --- a/libavdevice/avdevice.c
>> +++ b/libavdevice/avdevice.c
>> @@ -78,52 +78,6 @@ const char * avdevice_license(void)
>>      return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
>>  }
>>
>> -static void *device_next(void *prev, int output,
>> -                         AVClassCategory c1, AVClassCategory c2)
>> -{
>> -    const AVClass *pc;
>> -    AVClassCategory category = AV_CLASS_CATEGORY_NA;
>> -    do {
>> -        if (output) {
>> -            if (!(prev = av_oformat_next(prev)))
>> -                break;
>> -            pc = ((AVOutputFormat *)prev)->priv_class;
>> -        } else {
>> -            if (!(prev = av_iformat_next(prev)))
>> -                break;
>> -            pc = ((AVInputFormat *)prev)->priv_class;
>> -        }
>> -        if (!pc)
>> -            continue;
>> -        category = pc->category;
>> -    } while (category != c1 && category != c2);
>> -    return prev;
>> -}
>> -
>> -AVInputFormat *av_input_audio_device_next(AVInputFormat  *d)
>> -{
>> -    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,
>> -                       AV_CLASS_CATEGORY_DEVICE_INPUT);
>> -}
>> -
>> -AVInputFormat *av_input_video_device_next(AVInputFormat  *d)
>> -{
>> -    return device_next(d, 0, AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
>> -                       AV_CLASS_CATEGORY_DEVICE_INPUT);
>> -}
>> -
>> -AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d)
>> -{
>> -    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_AUDIO_OUTPUT,
>> -                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
>> -}
>> -
>> -AVOutputFormat *av_output_video_device_next(AVOutputFormat *d)
>> -{
>> -    return device_next(d, 1, AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
>> -                       AV_CLASS_CATEGORY_DEVICE_OUTPUT);
>> -}
>> -
>>  int avdevice_app_to_dev_control_message(struct AVFormatContext *s, enum AVAppToDevMessageType type,
>>                                          void *data, size_t data_size)
>>  {
>> diff --git a/libavdevice/avdevice.h b/libavdevice/avdevice.h
>> index ee94624..dd6ad93 100644
>> --- a/libavdevice/avdevice.h
>> +++ b/libavdevice/avdevice.h
>> @@ -66,6 +66,29 @@ const char *avdevice_configuration(void);
>>  const char *avdevice_license(void);
>>
>>  /**
>> + * Iterate over all registered output devices.
>> + *
>> + * @param opaque a pointer where libavdevice will store the iteration state. Must
>> + *               point to NULL to start the iteration.
>> + *
>> + * @return the next registered output device or NULL when the iteration is
>> + *         finished
>> + */
>> +const AVOutputFormat *av_outdev_iterate(void **opaque);
>> +
>> +/**
>> + * Iterate over all registered input devices.
>> + *
>> + * @param opaque a pointer where libavdevice will store the iteration state. Must
>> + *               point to NULL to start the iteration.
>> + *
>> + * @return the next registered input device or NULL when the iteration is
>> + *         finished
>> + */
>> +const AVInputFormat *av_indev_iterate(void **opaque);
>> +
>> +#if FF_API_NEXT
>> +/**
>>   * Initialize libavdevice and register all the input and output devices.
>>   */
>>  void avdevice_register_all(void);
>> @@ -77,6 +100,7 @@ void avdevice_register_all(void);
>>   * if d is non-NULL, returns the next registered input audio/video device after d
>>   * or NULL if d is the last one.
>>   */
>> +attribute_deprecated
>>  AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
>>
>>  /**
>> @@ -86,6 +110,7 @@ AVInputFormat *av_input_audio_device_next(AVInputFormat  *d);
>>   * if d is non-NULL, returns the next registered input audio/video device after d
>>   * or NULL if d is the last one.
>>   */
>> +attribute_deprecated
>>  AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
>>
>>  /**
>> @@ -95,6 +120,7 @@ AVInputFormat *av_input_video_device_next(AVInputFormat  *d);
>>   * if d is non-NULL, returns the next registered output audio/video device after d
>>   * or NULL if d is the last one.
>>   */
>> +attribute_deprecated
>>  AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
>>
>>  /**
>> @@ -104,7 +130,9 @@ AVOutputFormat *av_output_audio_device_next(AVOutputFormat *d);
>>   * if d is non-NULL, returns the next registered output audio/video device after d
>>   * or NULL if d is the last one.
>>   */
>> +attribute_deprecated
>>  AVOutputFormat *av_output_video_device_next(AVOutputFormat *d);
>> +#endif
>>
>>  typedef struct AVDeviceRect {
>>      int x;      /**< x coordinate of top left corner */
>> diff --git a/libavdevice/version.h b/libavdevice/version.h
>> index 0d4477f..892c4f3 100644
>> --- a/libavdevice/version.h
>> +++ b/libavdevice/version.h
>> @@ -47,4 +47,8 @@
>>   * the public API and may change, break or disappear at any time.
>>   */
>>
>> +#ifndef FF_API_NEXT
>> +#define FF_API_NEXT              (LIBAVDEVICE_VERSION_MAJOR < 59)
>> +#endif
>> +
>>  #endif /* AVDEVICE_VERSION_H */
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index 09c4213..40f592b 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -20,11 +20,15 @@
>>   */
>>
>>  #include "libavutil/thread.h"
>> +#include "libavdevice/avdevice.h"
>>  #include "avformat.h"
>>  #include "rtp.h"
>>  #include "rdt.h"
>>  #include "url.h"
>>  #include "version.h"
>> +#if FF_API_NEXT
>> +#include "internal.h"
>> +#endif
>>
>>  /* (de)muxers */
>>  extern AVOutputFormat ff_a64_muxer;
>> @@ -480,6 +484,7 @@ const AVOutputFormat *av_muxer_iterate(void **opaque)
>>  {
>>      uintptr_t i = (uintptr_t)*opaque;
>>      const AVOutputFormat *f = muxer_list[i];
>> +
>>      if (f)
>>          *opaque = (void*)(i + 1);
>>      return f;
>> @@ -498,6 +503,9 @@ const AVInputFormat *av_demuxer_iterate(void **opaque){
>>  FF_DISABLE_DEPRECATION_WARNINGS
>>  static AVOnce av_format_next_init = AV_ONCE_INIT;
>>
>> +static const AVInputFormat * const *indev_list = NULL;
>> +static const AVOutputFormat * const *outdev_list = NULL;
>> +
>>  static void av_format_init_next(void)
>>  {
>>      AVOutputFormat *prevout = NULL, *out;
>> @@ -510,30 +518,63 @@ static void av_format_init_next(void)
>>          prevout = out;
>>      }
>>
>> +    if (outdev_list) {
>> +        for (int j = 0; (out = (AVOutputFormat*)outdev_list[j]); j++) {
>> +            if (prevout)
>> +                prevout->next = out;
>> +            prevout = out;
>> +        }
>> +    }
>> +
>>      i = 0;
>>      while ((in = (AVInputFormat*)av_demuxer_iterate(&i))) {
>>          if (previn)
>>              previn->next = in;
>>          previn = in;
>>      }
>> +
>> +    if (indev_list) {
>> +        for (int j = 0; (in = (AVInputFormat*)indev_list[j]); j++) {
>> +            if (previn)
>> +                previn->next = in;
>> +            previn = in;
>> +        }
>> +    }
>> +
>> +}
>> +
>> +void avpriv_register_devices(const AVOutputFormat * const o[], const AVInputFormat * const i[])
>> +{
>> +    static AVMutex avpriv_register_devices_mutex = AV_MUTEX_INITIALIZER;
>> +    ff_mutex_lock(&avpriv_register_devices_mutex);
>> +    outdev_list = o;
>> +    indev_list = i;
>> +    av_format_init_next();
>> +    ff_mutex_unlock(&avpriv_register_devices_mutex);
>>  }
>>
>>  AVInputFormat *av_iformat_next(const AVInputFormat *f)
>>  {
>> +    void *i = 0;
>>      ff_thread_once(&av_format_next_init, av_format_init_next);
>> +
>>      if (f)
>>          return f->next;
>>      else
>> -        return demuxer_list[0];
>> +    /* If there are no demuxers but input devices, then return the first input device.
>> +     * This will still return null if both there are both no demuxers or input devices. */
>> +        return demuxer_list[0] ? (AVInputFormat*)demuxer_list[0] : (AVInputFormat*)av_indev_iterate(&i);
>
> This is dependency violation. libavformat should have no dependencies
> with libavcodec.

       ^ libavdevice.

On Tue, Feb 06, 2018 at 06:38:08AM +0700, Muhammad Faiz wrote:
> On Tue, Feb 6, 2018 at 6:35 AM, Muhammad Faiz <mfcc64@gmail.com> wrote:
> > [...]
> >
> > This is dependency violation. libavformat should have no dependencies
> > with libavcodec.
> 
>        ^ libavdevice.

Yes, this just needs to use the lists which are registered from the avpriv
function. I will fix that before I push.