[FFmpeg-devel] [PATCH] Add support for sndio to libavdevice

Stefano Sabatini stefano.sabatini-lala
Sun Aug 8 00:57:01 CEST 2010


On date Monday 2010-08-02 19:42:28 -0400, Brad encoded:
> sndio is a relatively new audio API utilized by OpenBSD.
> 
> Below is a patch to add sndio playback and record support
> to FFmpeg.
> 
> I believe I have touched everything that needs updating
> including documentation such as the recently added
> indevs.texi and outdevs.texi, but if not please let
> me know.
> 
> The sndio code was written by Jacob Meuser <jakemsr sdf lonestar org>
> 
> Please provide any feedback.
> 
> 
> Index: configure
> ===================================================================
> --- configure	(revision 24666)
> +++ configure	(working copy)
> @@ -1030,6 +1030,7 @@
>      sdl
>      sdl_video_size
>      setmode
> +    sndio_h
>      socklen_t
>      soundcard_h
>      poll_h
> @@ -1361,6 +1362,10 @@
>  libdc1394_indev_deps="libdc1394"
>  oss_indev_deps_any="soundcard_h sys_soundcard_h"
>  oss_outdev_deps_any="soundcard_h sys_soundcard_h"
> +sndio_indev_deps="sndio_h"
> +sndio_indev_extralibs="-lsndio"
> +sndio_outdev_deps="sndio_h"
> +sndio_outdev_extralibs="-lsndio"
>  v4l_indev_deps="linux_videodev_h"
>  v4l2_indev_deps_any="linux_videodev2_h sys_videoio_h"
>  vfwcap_indev_deps="capCreateCaptureWindow vfwcap_defines"
> @@ -2772,11 +2777,14 @@
>  
>  check_header sys/soundcard.h
>  check_header soundcard.h
> +check_header sndio.h
>  
>  enabled_any alsa_indev alsa_outdev && check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound
>  
>  enabled jack_indev && check_lib2 jack/jack.h jack_client_open -ljack
>  
> +enabled_any sndio_indev sndio_outdev && check_lib2 sndio.h sio_open -lsndio
> +
>  enabled x11grab                         &&
>  check_header X11/Xlib.h                 &&
>  check_header X11/extensions/XShm.h      &&
> Index: Changelog
> ===================================================================
> --- Changelog	(revision 24666)
> +++ Changelog	(working copy)
> @@ -27,9 +27,9 @@
>  - SubRip subtitle file muxer and demuxer
>  - Chinese AVS encoding via libxavs
>  - ffprobe -show_packets option added
> +- sndio support for playback and record
>  
>  
> -
>  version 0.6:
>  
>  - PB-frame decoding for H.263
> Index: doc/indevs.texi
> ===================================================================
> --- doc/indevs.texi	(revision 24666)
> +++ doc/indevs.texi	(working copy)
> @@ -133,6 +133,23 @@
>  For more information about OSS see:
>  @url{http://manuals.opensound.com/usersguide/dsp.html}
>  
> + at section sndio
> +
> +sndio input device.
> +
> +To enable this input device during configuration you need libsndio
> +installed on your system.
> +
> +The filename to provide to the input device is the device node
> +representing the sndio input device, and is usually set to
> + at file{/dev/audio0/}.

@file{/dev/audio0}, no trailing "/", here and below.

> +
> +For example to grab from @file{/dev/audio0/} using @file{ffmpeg} use the
> +command:
> + at example
> +ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
> + at end example
> +
>  @section video4linux and video4linux2
>  
>  Video4Linux and Video4Linux2 input video devices.
> Index: doc/outdevs.texi
> ===================================================================
> --- doc/outdevs.texi	(revision 24666)
> +++ doc/outdevs.texi	(working copy)
> @@ -30,4 +30,8 @@
>  
>  OSS (Open Sound System) output device.
>  
> + at section sndio
> +
> +sndio audio output device.
> +
>  @c man end OUTPUT DEVICES
> Index: libavdevice/alldevices.c
> ===================================================================
> --- libavdevice/alldevices.c	(revision 24666)
> +++ libavdevice/alldevices.c	(working copy)
> @@ -44,6 +44,7 @@
>      REGISTER_INDEV    (DV1394, dv1394);
>      REGISTER_INDEV    (JACK, jack);
>      REGISTER_INOUTDEV (OSS, oss);
> +    REGISTER_INOUTDEV (SNDIO, sndio);
>      REGISTER_INDEV    (V4L2, v4l2);
>      REGISTER_INDEV    (V4L, v4l);
>      REGISTER_INDEV    (VFWCAP, vfwcap);
> Index: libavdevice/sndio.c
> ===================================================================
> --- libavdevice/sndio.c	(revision 0)
> +++ libavdevice/sndio.c	(revision 0)
> @@ -0,0 +1,299 @@
> +/*
> + * sndio play and grab interface
> + * Copyright (c) 2010 Jacob Meuser
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#include "config.h"
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <stdint.h>
> +#include <string.h>
> +#include <unistd.h>
> +
> +#include <sndio.h>
> +
> +#include "libavutil/log.h"
> +#include "libavcodec/avcodec.h"
> +#include "libavformat/avformat.h"
> +
> +
> +typedef struct {
> +    struct sio_hdl *hdl;
> +    int sample_rate;
> +    int channels;
> +    int bps;
> +    enum CodecID codec_id;
> +    int buffer_size;
> +    uint8_t *buffer;
> +    int buffer_ptr;
> +    long long hwpos, softpos;
> +} AudioData;
> +
> +static void movecb(void *addr, int delta)
> +{
> +    AudioData *s = addr;
> +
> +    s->hwpos += delta * s->channels * s->bps;
> +}
> +
> +static int audio_open(AVFormatContext *s1, int is_output, const char *audio_device)
> +{
> +    AudioData *s = s1->priv_data;
> +    struct sio_hdl *hdl = NULL;
> +    struct sio_par par;
> +
> +    if (is_output)
> +        hdl = sio_open(audio_device, SIO_PLAY, 0);
> +    else
> +        hdl = sio_open(audio_device, SIO_REC, 0);

simpler:
hdl = sio_open(audio_device, is_output ? SIO_PLAY : SIO_REC, 0);

> +    if (hdl == NULL) {
> +        av_log(s1, AV_LOG_ERROR, "could not open sndio device\n");
> +        return AVERROR(EIO);
> +    }
> +
> +    sio_initpar(&par);
> +    par.bits = 16;
> +    par.sig = 1;
> +    par.le = SIO_LE_NATIVE;

> +    if (is_output)
> +        par.pchan = s->channels;
> +    else
> +        par.rchan = s->channels;

This also could be simplified.

> +    par.rate = s->sample_rate;
> +

> +    if (!sio_setpar(hdl, &par) || !sio_getpar(hdl, &par)) {
> +        av_log(s1, AV_LOG_ERROR, "error setting sndio parameters\n");
> +        goto fail;
> +    }

"Impossible to set sndio parameters\n"
even better would be to print an error description.

> +
> +    if (par.bits != 16 || par.sig != 1 || par.le != SIO_LE_NATIVE ||
> +      (is_output && (par.pchan != s->channels)) ||
> +      (!is_output && (par.rchan != s->channels)) ||
> +      (par.rate != s->sample_rate)) {
> +        av_log(s1, AV_LOG_ERROR, "could not set appropriate sndio parameters\n");
> +        goto fail;
> +    }
> +
> +    s->buffer_size = par.round * par.bps *
> +      (is_output ? par.pchan : par.rchan);
> +
> +    s->buffer = av_malloc(s->buffer_size);
> +    if (s->buffer == NULL) {
> +        av_log(s1, AV_LOG_ERROR, "could not allocate buffer\n");
> +        goto fail;
> +    }
> +

> +    if (par.le)
> +        s->codec_id = CODEC_ID_PCM_S16LE;
> +    else
> +        s->codec_id = CODEC_ID_PCM_S16BE;
> +
> +    if (is_output)
> +        s->channels = par.pchan;
> +    else
> +        s->channels = par.rchan;

-6 lines using the ? : construct.

> +
> +    s->sample_rate = par.rate;
> +    s->bps = par.bps;
> +
> +    sio_onmove(hdl, movecb, s);
> +
> +    if (!sio_start(hdl)) {
> +        av_log(s1, AV_LOG_ERROR, "could not start sndio\n");
> +        goto fail;
> +    }
> +
> +    s->hdl = hdl;
> +
> +    return 0;
> +
> +fail:
> +    if (s->buffer)
> +        av_free(s->buffer);
> +    if (hdl)
> +        sio_close(hdl);
> +    return AVERROR(EIO);
> +}
> +
> +static int audio_close(AudioData *s)
> +{
> +    if (s->buffer)
> +        av_free(s->buffer);
> +    if (s->hdl)
> +        sio_close(s->hdl);
> +    return 0;
> +}
> +
> +/* sound output support */
> +static int audio_write_header(AVFormatContext *s1)
> +{
> +    AudioData *s = s1->priv_data;
> +    AVStream *st;
> +    int ret;
> +
> +    st = s1->streams[0];
> +    s->sample_rate = st->codec->sample_rate;
> +    s->channels = st->codec->channels;
> +    ret = audio_open(s1, 1, s1->filename);
> +    if (ret < 0) {
> +        return AVERROR(EIO);
> +    } else {
> +        return 0;
> +    }
> +}
> +
> +static int audio_write_packet(AVFormatContext *s1, AVPacket *pkt)
> +{
> +    AudioData *s = s1->priv_data;
> +    int len, ret;
> +    int size = pkt->size;
> +    uint8_t *buf= pkt->data;
> +
> +    while (size > 0) {
> +        len = s->buffer_size - s->buffer_ptr;
> +        if (len > size)
> +            len = size;
> +        memcpy(s->buffer + s->buffer_ptr, buf, len);
> +        buf += len;
> +        size -= len;
> +        s->buffer_ptr += len;
> +        if (s->buffer_ptr >= s->buffer_size) {
> +            ret = sio_write(s->hdl, s->buffer, s->buffer_size);
> +            if (ret == 0 || sio_eof(s->hdl))
> +                return AVERROR(EIO);
> +            s->softpos += ret;
> +            s->buffer_ptr = 0;
> +        }
> +    }
> +    return 0;
> +}
> +
> +static int audio_write_trailer(AVFormatContext *s1)
> +{
> +    AudioData *s = s1->priv_data;
> +
> +    audio_close(s);
> +    return 0;
> +}
> +
> +/* grab support */
> +
> +static int audio_read_header(AVFormatContext *s1, AVFormatParameters *ap)
> +{
> +    AudioData *s = s1->priv_data;
> +    AVStream *st;
> +    int ret;
> +
> +    if (ap->sample_rate <= 0 || ap->channels <= 0)

> +        return -1;

AVERROR(EINVAL);

> +
> +    st = av_new_stream(s1, 0);
> +    if (!st) {
> +        return AVERROR(ENOMEM);
> +    }
> +    s->sample_rate = ap->sample_rate;
> +    s->channels = ap->channels;
> +
> +    ret = audio_open(s1, 0, s1->filename);
> +    if (ret < 0) {
> +        return AVERROR(EIO);
> +    }
> +
> +    /* take real parameters */
> +    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
> +    st->codec->codec_id = s->codec_id;
> +    st->codec->sample_rate = s->sample_rate;
> +    st->codec->channels = s->channels;
> +
> +    av_set_pts_info(st, 64, 1, 1000000);  /* 64 bits pts in us */
> +    return 0;
> +}
> +
> +static int audio_read_packet(AVFormatContext *s1, AVPacket *pkt)
> +{
> +    AudioData *s = s1->priv_data;
> +    int ret, bdelay;
> +    int64_t cur_time;
> +
> +    if ((ret=av_new_packet(pkt, s->buffer_size)) < 0)
> +        return ret;
> +
> +    ret = sio_read(s->hdl, pkt->data, pkt->size);
> +    if (ret == 0 || sio_eof(s->hdl)) {
> +        av_free_packet(pkt);
> +        pkt->size = 0;
> +        return AVERROR_EOF;
> +    }
> +    pkt->size = ret;
> +    s->softpos += ret;
> +
> +    /* compute pts of the start of the packet */
> +    cur_time = av_gettime();
> +
> +    bdelay = ret + s->hwpos - s->softpos;
> +
> +    /* convert to wanted units */
> +    pkt->pts = cur_time;
> +
> +    return 0;
> +}
> +
> +static int audio_read_close(AVFormatContext *s1)
> +{
> +    AudioData *s = s1->priv_data;
> +
> +    audio_close(s);
> +    return 0;
> +}
> +
> +#if CONFIG_SNDIO_INDEV
> +AVInputFormat sndio_demuxer = {
> +    "sndio",
> +    NULL_IF_CONFIG_SMALL("sndio audio capture"),
> +    sizeof(AudioData),
> +    NULL,
> +    audio_read_header,
> +    audio_read_packet,
> +    audio_read_close,
> +    .flags = AVFMT_NOFILE,
> +};
> +#endif
> +
> +#if CONFIG_SNDIO_OUTDEV
> +AVOutputFormat sndio_muxer = {
> +    "sndio",
> +    NULL_IF_CONFIG_SMALL("sndio audio playback"),
> +    "",
> +    "",
> +    sizeof(AudioData),
> +    /* XXX: we make the assumption that the soundcard accepts this format */
> +    /* XXX: find better solution with "preinit" method, needed also in
> +       other formats */
> +#if HAVE_BIGENDIAN
> +    CODEC_ID_PCM_S16BE,
> +#else
> +    CODEC_ID_PCM_S16LE,
> +#endif
> +    CODEC_ID_NONE,
> +    audio_write_header,
> +    audio_write_packet,
> +    audio_write_trailer,
> +    .flags = AVFMT_NOFILE,
> +};

maybe we should use designated init for all the fields, more robust
and don't break in case of ABI breaks (e.g. in case of major bumps).

Regards.
-- 
FFmpeg = Fostering and Fanciful Mystic Practical Extroverse Ghost



More information about the ffmpeg-devel mailing list