| Message ID | CAHStOZ6crquW40AZtUHJy2oiOy5KB8ULqWQWm-RSyez_BMTAgg@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
On 04/05/2018 06:42 PM, Maxime Jourdan wrote: > Reduce the minimum amount of CAPTURE and OUTPUT buffers to 1. makes sense to me if that is indeed the case. could you provide a real life use case? > > There are drivers that may work with such drastic settings, > and FFmpeg doesn't complain. > --- > libavcodec/v4l2_m2m.h | 2 +- > libavcodec/v4l2_m2m_dec.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h > index 452bf0d9bc..68e4e5d6c6 100644 > --- a/libavcodec/v4l2_m2m.h > +++ b/libavcodec/v4l2_m2m.h > @@ -38,7 +38,7 @@ > #define V4L_M2M_DEFAULT_OPTS \ > { "num_output_buffers", "Number of buffers in the output context",\ > - OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, > 6, INT_MAX, FLAGS } > + OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, > 1, INT_MAX, FLAGS } > typedef struct V4L2m2mContext { > char devname[PATH_MAX]; > diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c > index bca45be148..5196680bbb 100644 > --- a/libavcodec/v4l2_m2m_dec.c > +++ b/libavcodec/v4l2_m2m_dec.c > @@ -198,7 +198,7 @@ static av_cold int v4l2_decode_init(AVCodecContext > *avctx) > static const AVOption options[] = { > V4L_M2M_DEFAULT_OPTS, > { "num_capture_buffers", "Number of buffers in the capture context", > - OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, > 20, INT_MAX, FLAGS }, > + OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 1, > INT_MAX, FLAGS }, > { NULL}, > }; > -- > 2.16.2
The AMLogic meson V4L2 M2M I'm developping (https://github.com/Elyotna/linux) can fare with only one OUTPUT buffer for data input. Granted, only 1 CAPTURE buffer is probably not going to cut it, but still, I don't see the reason behind restricting the FFmpeg user to try with 1 (in the end the driver will adjust the min/max buffers anyway). 2018-04-05 22:14 GMT+02:00 Jorge Ramirez-Ortiz <jramirez@baylibre.com>: > On 04/05/2018 06:42 PM, Maxime Jourdan wrote: > >> Reduce the minimum amount of CAPTURE and OUTPUT buffers to 1. >> > > makes sense to me if that is indeed the case. > could you provide a real life use case? > > > >> There are drivers that may work with such drastic settings, >> and FFmpeg doesn't complain. >> --- >> libavcodec/v4l2_m2m.h | 2 +- >> libavcodec/v4l2_m2m_dec.c | 2 +- >> 2 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h >> index 452bf0d9bc..68e4e5d6c6 100644 >> --- a/libavcodec/v4l2_m2m.h >> +++ b/libavcodec/v4l2_m2m.h >> @@ -38,7 +38,7 @@ >> #define V4L_M2M_DEFAULT_OPTS \ >> { "num_output_buffers", "Number of buffers in the output context",\ >> - OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, >> INT_MAX, FLAGS } >> + OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 1, >> INT_MAX, FLAGS } >> typedef struct V4L2m2mContext { >> char devname[PATH_MAX]; >> diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c >> index bca45be148..5196680bbb 100644 >> --- a/libavcodec/v4l2_m2m_dec.c >> +++ b/libavcodec/v4l2_m2m_dec.c >> @@ -198,7 +198,7 @@ static av_cold int v4l2_decode_init(AVCodecContext >> *avctx) >> static const AVOption options[] = { >> V4L_M2M_DEFAULT_OPTS, >> { "num_capture_buffers", "Number of buffers in the capture context", >> - OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 20, >> INT_MAX, FLAGS }, >> + OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 1, >> INT_MAX, FLAGS }, >> { NULL}, >> }; >> -- >> 2.16.2 >> > >
diff --git a/libavcodec/v4l2_m2m.h b/libavcodec/v4l2_m2m.h index 452bf0d9bc..68e4e5d6c6 100644 --- a/libavcodec/v4l2_m2m.h +++ b/libavcodec/v4l2_m2m.h @@ -38,7 +38,7 @@ #define V4L_M2M_DEFAULT_OPTS \ { "num_output_buffers", "Number of buffers in the output context",\ - OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 6, INT_MAX, FLAGS } + OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 1, INT_MAX, FLAGS } typedef struct V4L2m2mContext { char devname[PATH_MAX]; diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c index bca45be148..5196680bbb 100644 --- a/libavcodec/v4l2_m2m_dec.c +++ b/libavcodec/v4l2_m2m_dec.c @@ -198,7 +198,7 @@ static av_cold int v4l2_decode_init(AVCodecContext *avctx) static const AVOption options[] = { V4L_M2M_DEFAULT_OPTS, { "num_capture_buffers", "Number of buffers in the capture context", - OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 20, INT_MAX, FLAGS }, + OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 1, INT_MAX, FLAGS },
Reduce the minimum amount of CAPTURE and OUTPUT buffers to 1. There are drivers that may work with such drastic settings, and FFmpeg doesn't complain. --- libavcodec/v4l2_m2m.h | 2 +- libavcodec/v4l2_m2m_dec.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) { NULL}, };