[FFmpeg-devel] [PATCH 2/3 v2] decklink: new option 'format_code' to set video format by fourCC

Marton Balint cus at passwd.hu
Sat Mar 18 03:14:24 EET 2017



On Fri, 17 Mar 2017, Matthias Hunstock wrote:

> Signed-off-by: Matthias Hunstock <atze at fem.tu-ilmenau.de>
> ---
> libavdevice/decklink_common.cpp | 17 +++++++++++++----
> libavdevice/decklink_common_c.h |  1 +
> libavdevice/decklink_dec.cpp    |  5 +++--
> libavdevice/decklink_dec_c.c    |  1 +
> libavdevice/decklink_enc_c.c    |  1 +
> 5 files changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/libavdevice/decklink_common.cpp b/libavdevice/decklink_common.cpp
> index 82b3a0c..a75ccc1 100644
> --- a/libavdevice/decklink_common.cpp
> +++ b/libavdevice/decklink_common.cpp
> @@ -33,6 +33,7 @@ extern "C" {
> #include "libavformat/avformat.h"
> #include "libavformat/internal.h"
> #include "libavutil/imgutils.h"
> +#include "libavutil/intreadwrite.h"
> #include "libavutil/bswap.h"
> }
> 
> @@ -158,8 +159,8 @@ int ff_decklink_set_format(AVFormatContext *avctx,
>     int i = 1;
>     HRESULT res;
> 
> -    av_log(avctx, AV_LOG_DEBUG, "Trying to find mode for frame size %dx%d, frame timing %d/%d, field order %d, direction %d, mode number %d\n",
> -        width, height, tb_num, tb_den, field_order, direction, num);
> +    av_log(avctx, AV_LOG_DEBUG, "Trying to find mode for frame size %dx%d, frame timing %d/%d, field order %d, direction %d, mode number %d, format code %s\n",
> +        width, height, tb_num, tb_den, field_order, direction, num, (cctx->format_code) ? cctx->format_code : "(unset)");
>
>     if (ctx->duplex_mode) {
>         DECKLINK_BOOL duplex_supported = false;
> @@ -196,12 +197,18 @@ int ff_decklink_set_format(AVFormatContext *avctx,
>             return AVERROR(EIO);
>     }
> 
> +    BMDDisplayMode target_mode = 0;
> +    char format_buf[] = "     ";
> +    if (cctx->format_code)
> +        av_strlcpy(format_buf, cctx->format_code, sizeof(format_buf));

Are you sure this does what you want it to do? The null terminator should 
noy be copied to format_buf.

> +    target_mode = av_bswap32(AV_RL32(format_buf));

I think you can do this in one step with AV_RB32 (the big endian pair of 
AV_RL32)

>     AVRational target_tb = av_make_q(tb_num, tb_den);
>     ctx->bmd_mode = bmdModeUnknown;
>     while ((ctx->bmd_mode == bmdModeUnknown) && itermode->Next(&mode) == S_OK) {
>         BMDTimeValue bmd_tb_num, bmd_tb_den;
>         int bmd_width  = mode->GetWidth();
>         int bmd_height = mode->GetHeight();
> +        BMDDisplayMode bmd_mode = mode->GetDisplayMode();
>         BMDFieldDominance bmd_field_dominance = mode->GetFieldDominance();
>
>         mode->GetFrameRate(&bmd_tb_num, &bmd_tb_den);
> @@ -210,8 +217,10 @@ int ff_decklink_set_format(AVFormatContext *avctx,
>         if ((bmd_width == width &&
>              bmd_height == height &&
>              !av_cmp_q(mode_tb, target_tb) &&
> -             field_order_eq(field_order, bmd_field_dominance)) || i == num) {
> -            ctx->bmd_mode   = mode->GetDisplayMode();
> +             field_order_eq(field_order, bmd_field_dominance))
> +             || i == num
> +             || target_mode == bmd_mode) {
> +            ctx->bmd_mode   = bmd_mode;
>             ctx->bmd_width  = bmd_width;
>             ctx->bmd_height = bmd_height;
>             ctx->bmd_tb_den = bmd_tb_den;
> diff --git a/libavdevice/decklink_common_c.h b/libavdevice/decklink_common_c.h
> index d565631..72c5f9a 100644
> --- a/libavdevice/decklink_common_c.h
> +++ b/libavdevice/decklink_common_c.h
> @@ -47,6 +47,7 @@ struct decklink_cctx {
>     int audio_input;
>     int video_input;
>     int draw_bars;
> +    char *format_code;
> };
> 
> #endif /* AVDEVICE_DECKLINK_COMMON_C_H */
> diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
> index 7df841b..ffe65db 100644
> --- a/libavdevice/decklink_dec.cpp
> +++ b/libavdevice/decklink_dec.cpp
> @@ -539,9 +539,10 @@ av_cold int ff_decklink_read_header(AVFormatContext *avctx)
>         goto error;
>     }
> 
> -    if (mode_num > 0) {
> +    if (mode_num > 0 || cctx->format_code) {
>         if (ff_decklink_set_format(avctx, DIRECTION_IN, mode_num) < 0) {
> -            av_log(avctx, AV_LOG_ERROR, "Could not set mode %d for %s\n", mode_num, fname);
> +            av_log(avctx, AV_LOG_ERROR, "Could not set mode number %d or format code %s for %s\n",
> +                mode_num, (cctx->format_code) ? cctx->format_code : "(unset)", fname);
>             ret = AVERROR(EIO);
>             goto error;
>         }
> diff --git a/libavdevice/decklink_dec_c.c b/libavdevice/decklink_dec_c.c
> index 31818d2..d4ae4e5 100644
> --- a/libavdevice/decklink_dec_c.c
> +++ b/libavdevice/decklink_dec_c.c
> @@ -31,6 +31,7 @@
> 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 },
> +    { "format_code",  "set format by fourcc"    , OFFSET(format_code),  AV_OPT_TYPE_STRING, { .str = NULL}, 3, 4, DEC },
>     { "bm_v210",      "v210 10 bit per channel" , OFFSET(v210),         AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, DEC },
>     { "teletext_lines", "teletext lines bitmask", OFFSET(teletext_lines), AV_OPT_TYPE_INT64, { .i64 = 0   }, 0, 0x7ffffffffLL, DEC, "teletext_lines"},
>     { "standard",     NULL,                                           0,  AV_OPT_TYPE_CONST, { .i64 = 0x7fff9fffeLL}, 0, 0,    DEC, "teletext_lines"},
> diff --git a/libavdevice/decklink_enc_c.c b/libavdevice/decklink_enc_c.c
> index 03734f8..76a040c 100644
> --- a/libavdevice/decklink_enc_c.c
> +++ b/libavdevice/decklink_enc_c.c
> @@ -30,6 +30,7 @@
> static const AVOption options[] = {
>     { "list_devices", "list available devices"  , OFFSET(list_devices), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, ENC },
>     { "list_formats", "list supported formats"  , OFFSET(list_formats), AV_OPT_TYPE_INT   , { .i64 = 0   }, 0, 1, ENC },
> +    { "format_code",  "force format by fourcc"  , OFFSET(format_code),  AV_OPT_TYPE_STRING, { .str = NULL}, 3, 4, ENC },
>     { "preroll"     , "video preroll in seconds", OFFSET(preroll     ), AV_OPT_TYPE_DOUBLE, { .dbl = 0.5 }, 0, 5, ENC },
>     { NULL },

Please make outdev support a separate patch if you insist on it, I am 
still not convinced that it is a good idea to support this for outdev and 
allowing mismatching width/height/framerate at the same time.

On the other hand, you can merge the documentation into this patch.

Thanks,
Marton


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