As it is already written in the documentation, BMD DeckLink cards
are capable of capturing 2, 8 or 16 audio channels (for SDI Inputs).
Currently the value is hardcoded to 2. Introduces new option.
Signed-off-by: Matthias Hunstock <a...@fem.tu-ilmenau.de>
---
doc/indevs.texi | 13 ++++++++++++-
libavdevice/decklink_common_c.h | 1 +
libavdevice/decklink_dec.cpp | 16 ++++++++++++++--
libavdevice/decklink_dec_c.c | 2 ++
4 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/doc/indevs.texi b/doc/indevs.texi
index 6cf626d..6003b9f 100644
--- a/doc/indevs.texi
+++ b/doc/indevs.texi
@@ -218,7 +218,8 @@ On Windows, you need to run the IDL files through
@command{widl}.
DeckLink is very picky about the formats it supports. Pixel format is
uyvy422 or v210, framerate and video size must be determined for your device
with
@command{-list_formats 1}. Audio sample rate is always 48 kHz and the number
-of channels can be 2, 8 or 16.
+of channels can be 2, 8 or 16. Note that all audio channels are bundled in one
single
+audio track.
@subsection Options
@@ -236,6 +237,10 @@ Defaults to @option{false}.
If set to @samp{1}, video is captured in 10 bit v210 instead
of uyvy422. Not all Blackmagic devices support this option.
+@item channels
+Defines number of audio channels to capture. Must be @samp{2}, @samp{8} or
@samp{16}.
+Defaults to @samp{2}.
+
@end table
@subsection Examples
@@ -266,6 +271,12 @@ Capture video clip at 1080i50 10 bit:
ffmpeg -bm_v210 1 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec copy
-vcodec copy output.avi
@end example
+@item
+Capture video clip at 1080i50 with 16 audio channels:
+@example
+ffmpeg -channels 16 -f decklink -i 'UltraStudio Mini Recorder@@11' -acodec
copy -vcodec copy output.avi
+@end example
+
@end itemize
@section dshow
diff --git a/libavdevice/decklink_common_c.h b/libavdevice/decklink_common_c.h
index fb2b788..403956f 100644
--- a/libavdevice/decklink_common_c.h
+++ b/libavdevice/decklink_common_c.h
@@ -29,5 +29,6 @@ struct decklink_cctx {
int list_formats;
double preroll;
int v210;
+ int audio_channels;
};
diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
index 89f93de..1588933 100644
--- a/libavdevice/decklink_dec.cpp
+++ b/libavdevice/decklink_dec.cpp
@@ -381,6 +381,17 @@ av_cold int ff_decklink_read_header(AVFormatContext *avctx)
ctx->preroll = cctx->preroll;
cctx->ctx = ctx;
+ /* Check audio channel option for valid values: 2, 8 or 16 */
+ switch (cctx->audio_channels) {
+ case 2:
+ case 8:
+ case 16:
+ break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Value of channels option must be one
of 2, 8 or 16\n");
+ return AVERROR(EINVAL);
+ }
+
iter = CreateDeckLinkIteratorInstance();
if (!iter) {
av_log(avctx, AV_LOG_ERROR, "Could not create DeckLink iterator\n");
@@ -458,7 +469,7 @@ av_cold int ff_decklink_read_header(AVFormatContext *avctx)
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_PCM_S16LE;
st->codec->sample_rate = bmdAudioSampleRate48kHz;
- st->codec->channels = 2;
+ st->codec->channels = cctx->audio_channels;
avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
ctx->audio_st=st;
@@ -488,7 +499,8 @@ av_cold int ff_decklink_read_header(AVFormatContext *avctx)
ctx->video_st=st;
- result = ctx->dli->EnableAudioInput(bmdAudioSampleRate48kHz,
bmdAudioSampleType16bitInteger, 2);
+ av_log(avctx, AV_LOG_VERBOSE, "Using %d input audio channels\n",
ctx->audio_st->codec->channels);
+ result = ctx->dli->EnableAudioInput(bmdAudioSampleRate48kHz,
bmdAudioSampleType16bitInteger, ctx->audio_st->codec->channels);
if (result != S_OK) {
av_log(avctx, AV_LOG_ERROR, "Cannot enable audio input\n");
diff --git a/libavdevice/decklink_dec_c.c b/libavdevice/decklink_dec_c.c
index b1a65e6..487bfd6 100644
--- a/libavdevice/decklink_dec_c.c
+++ b/libavdevice/decklink_dec_c.c
@@ -32,6 +32,7 @@ static const AVOption options[] = {
{ "list_devices", "list available devices" , OFFSET(list_devices),
AV_OPT_TYPE_INT , { .i64 = 0 }, 0, 1, DEC },
{ "list_formats", "list supported formats" , OFFSET(list_formats),
AV_OPT_TYPE_INT , { .i64 = 0 }, 0, 1, DEC },
{ "bm_v210", "v210 10 bit per channel" , OFFSET(v210),
AV_OPT_TYPE_INT , { .i64 = 0 }, 0, 1, DEC },
+ { "channels", "number of audio channels", OFFSET(audio_channels),
AV_OPT_TYPE_INT , { .i64 = 2 }, 2, 16, DEC },
{ NULL },
};
--
2.4.10
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