[FFmpeg-devel] [PATCH 2/4] libavdevice/decklink: add support for -sources and -sinks arguments

Marton Balint cus at passwd.hu
Sat Sep 30 23:02:51 EEST 2017



On Tue, 26 Sep 2017, Devin Heitmueller wrote:

> Add support for enumerating the sources/sinks via the ffmpeg
> command line options, as opposed to having to create a real pipeline
> and use the "-list_devices" option which does exit() after dumping
> out the options.
>
> Note that this patch preserves the existing "-list_devices" option,
> but now shares common code for the actual enumeration.
>
> Signed-off-by: Devin Heitmueller <dheitmueller at ltnglobal.com>
> ---
> libavdevice/decklink_common.cpp | 52 +++++++++++++++++++++++++++++++++++++----
> libavdevice/decklink_common.h   |  2 +-
> libavdevice/decklink_dec.cpp    | 22 ++++++++++++++++-
> libavdevice/decklink_dec.h      |  1 +
> libavdevice/decklink_dec_c.c    |  1 +
> libavdevice/decklink_enc.cpp    | 22 ++++++++++++++++-
> libavdevice/decklink_enc.h      |  1 +
> libavdevice/decklink_enc_c.c    |  1 +
> 8 files changed, 95 insertions(+), 7 deletions(-)
>
> diff --git a/libavdevice/decklink_common.cpp b/libavdevice/decklink_common.cpp
> index 7745575d0e..86d6fbb74b 100644
> --- a/libavdevice/decklink_common.cpp
> +++ b/libavdevice/decklink_common.cpp
> @@ -37,6 +37,7 @@ extern "C" {
> #include "libavutil/imgutils.h"
> #include "libavutil/intreadwrite.h"
> #include "libavutil/bswap.h"
> +#include "avdevice.h"
> }
> 
> #include "decklink_common.h"
> @@ -261,24 +262,67 @@ int ff_decklink_set_format(AVFormatContext *avctx, decklink_direction_t directio
>     return ff_decklink_set_format(avctx, 0, 0, 0, 0, AV_FIELD_UNKNOWN, direction, num);
> }
> 
> -int ff_decklink_list_devices(AVFormatContext *avctx)
> +int ff_decklink_list_devices(AVFormatContext *avctx,
> +			     struct AVDeviceInfoList *device_list,
> +			     int show_inputs, int show_outputs)
> {
>     IDeckLink *dl = NULL;
>     IDeckLinkIterator *iter = CreateDeckLinkIteratorInstance();
> +    int ret = 0;
> +
>     if (!iter) {
>         av_log(avctx, AV_LOG_ERROR, "Could not create DeckLink iterator\n");
>         return AVERROR(EIO);
>     }
> -    av_log(avctx, AV_LOG_INFO, "Blackmagic DeckLink devices:\n");
> +
>     while (iter->Next(&dl) == S_OK) {

This probably needs an additional && ret == 0 condition, if there was an 
ENOMEM error, you want to return instantly instead of trying with the next 
device, and ignoring the ENOMEM.

> +        IDeckLinkOutput *output_config;
> +        IDeckLinkInput *input_config;
>         const char *displayName;
> +        AVDeviceInfo *new_device = NULL;
> +        int add = 0;
> +
>         ff_decklink_get_display_name(dl, &displayName);
> -        av_log(avctx, AV_LOG_INFO, "\t'%s'\n", displayName);
> +
> +        if (show_outputs) {
> +            if (dl->QueryInterface(IID_IDeckLinkOutput, (void **)&output_config) == S_OK) {
> +                output_config->Release();
> +                add = 1;
> +            }
> +        }
> +
> +        if (show_inputs) {
> +            if (dl->QueryInterface(IID_IDeckLinkInput, (void **)&input_config) == S_OK) {
> +                input_config->Release();
> +                add = 1;
> +            }
> +        }
> +
> +        if (add == 1) {
> +            new_device = (AVDeviceInfo *) av_mallocz(sizeof(AVDeviceInfo));
> +            if (!new_device) {
> +                ret = AVERROR(ENOMEM);
> +                goto next;
> +            }
> +            new_device->device_name = av_strdup(displayName);
> +            new_device->device_description = av_strdup(displayName);
> +            if (!new_device->device_description || !new_device->device_name) {

you might leak device_name here.

> +                ret = AVERROR(ENOMEM);
> +                goto next;
> +            }
> +
> +            if ((ret = av_dynarray_add_nofree(&device_list->devices,
> +                                              &device_list->nb_devices, new_device)) < 0) {

you should free the struct on error here I think

> +                goto next;
> +            }
> +        }
> +
> +    next:
>         av_free((void *) displayName);

av_freep

>         dl->Release();
>     }
>     iter->Release();
> -    return 0;
> +    return ret;
> }
> 
> int ff_decklink_list_formats(AVFormatContext *avctx, decklink_direction_t direction)
> diff --git a/libavdevice/decklink_common.h b/libavdevice/decklink_common.h
> index 749eb0f8b8..f81b33ada4 100644
> --- a/libavdevice/decklink_common.h
> +++ b/libavdevice/decklink_common.h
> @@ -135,7 +135,7 @@ static const BMDVideoConnection decklink_video_connection_map[] = {
> HRESULT ff_decklink_get_display_name(IDeckLink *This, const char **displayName);
> int ff_decklink_set_format(AVFormatContext *avctx, int width, int height, int tb_num, int tb_den, enum AVFieldOrder field_order, decklink_direction_t direction = DIRECTION_OUT, int num = 0);
> int ff_decklink_set_format(AVFormatContext *avctx, decklink_direction_t direction, int num);
> -int ff_decklink_list_devices(AVFormatContext *avctx);
> +int ff_decklink_list_devices(AVFormatContext *avctx, struct AVDeviceInfoList *device_list, int show_inputs, int show_outputs);
> int ff_decklink_list_formats(AVFormatContext *avctx, decklink_direction_t direction = DIRECTION_OUT);
> void ff_decklink_cleanup(AVFormatContext *avctx);
> int ff_decklink_init_device(AVFormatContext *avctx, const char* name);
> diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
> index c271ff3639..cb282055c6 100644
> --- a/libavdevice/decklink_dec.cpp
> +++ b/libavdevice/decklink_dec.cpp
> @@ -38,6 +38,7 @@ extern "C" {
> #include "libavutil/time.h"
> #include "libavutil/mathematics.h"
> #include "libavutil/reverse.h"
> +#include "avdevice.h"
> #if CONFIG_LIBZVBI
> #include <libzvbi.h>
> #endif
> @@ -647,7 +648,21 @@ av_cold int ff_decklink_read_header(AVFormatContext *avctx)
>
>     /* List available devices. */
>     if (ctx->list_devices) {
> -        ff_decklink_list_devices(avctx);
> +        struct AVDeviceInfoList *device_list = NULL;
> +        int ret;
> +
> +        device_list = (struct AVDeviceInfoList *) av_mallocz(sizeof(AVDeviceInfoList));
> +        if (!device_list)
> +            return AVERROR(ENOMEM);
> +
> +        ret = ff_decklink_list_devices(avctx, device_list, 1, 0);
> +        if (ret == 0) {
> +            av_log(avctx, AV_LOG_INFO, "Blackmagic DeckLink input devices:\n");
> +            for (int i = 0; i < device_list->nb_devices; i++) {
> +                av_log(avctx, AV_LOG_INFO, "\t'%s'\n", device_list->devices[i]->device_name);
> +            }
> +        }
> +        avdevice_free_list_devices(&device_list);
>         return AVERROR_EXIT;
>     }
> 
> @@ -810,4 +825,9 @@ int ff_decklink_read_packet(AVFormatContext *avctx, AVPacket *pkt)
>     return 0;
> }
> 
> +int ff_decklink_list_input_devices(AVFormatContext *avctx, struct AVDeviceInfoList *device_list)
> +{
> +    return ff_decklink_list_devices(avctx, device_list, 1, 0);
> +}
> +
> } /* extern "C" */
> diff --git a/libavdevice/decklink_dec.h b/libavdevice/decklink_dec.h
> index 9b71870deb..fbfbe6280e 100644
> --- a/libavdevice/decklink_dec.h
> +++ b/libavdevice/decklink_dec.h
> @@ -29,6 +29,7 @@ extern "C" {
> int ff_decklink_read_header(AVFormatContext *avctx);
> int ff_decklink_read_packet(AVFormatContext *avctx, AVPacket *pkt);
> int ff_decklink_read_close(AVFormatContext *avctx);
> +int ff_decklink_list_input_devices(AVFormatContext *avctx, struct AVDeviceInfoList *device_list);
> 
> #ifdef __cplusplus
> } /* extern "C" */
> diff --git a/libavdevice/decklink_dec_c.c b/libavdevice/decklink_dec_c.c
> index e2118a619c..992c21a160 100644
> --- a/libavdevice/decklink_dec_c.c
> +++ b/libavdevice/decklink_dec_c.c
> @@ -83,6 +83,7 @@ AVInputFormat ff_decklink_demuxer = {
>     .flags          = AVFMT_NOFILE,
>     .priv_class     = &decklink_demuxer_class,
>     .priv_data_size = sizeof(struct decklink_cctx),
> +    .get_device_list = ff_decklink_list_input_devices,
>     .read_header   = ff_decklink_read_header,
>     .read_packet   = ff_decklink_read_packet,
>     .read_close    = ff_decklink_read_close,
> diff --git a/libavdevice/decklink_enc.cpp b/libavdevice/decklink_enc.cpp
> index 25ce7d026c..0f654faa19 100644
> --- a/libavdevice/decklink_enc.cpp
> +++ b/libavdevice/decklink_enc.cpp
> @@ -33,6 +33,7 @@ extern "C" {
> extern "C" {
> #include "libavformat/avformat.h"
> #include "libavutil/imgutils.h"
> +#include "avdevice.h"
> }
> 
> #include "decklink_common.h"
> @@ -337,7 +338,21 @@ av_cold int ff_decklink_write_header(AVFormatContext *avctx)
>
>     /* List available devices. */
>     if (ctx->list_devices) {
> -        ff_decklink_list_devices(avctx);
> +        struct AVDeviceInfoList *device_list = NULL;
> +        int ret;
> +
> +        device_list = (struct AVDeviceInfoList *) av_mallocz(sizeof(AVDeviceInfoList));
> +        if (!device_list)
> +            return AVERROR(ENOMEM);
> +
> +        ret = ff_decklink_list_devices(avctx, device_list, 0, 1);
> +        if (ret == 0) {
> +            av_log(avctx, AV_LOG_INFO, "Blackmagic DeckLink output devices:\n");
> +            for (int i = 0; i < device_list->nb_devices; i++) {
> +                av_log(avctx, AV_LOG_INFO, "\t'%s'\n", device_list->devices[i]->device_name);
> +            }
> +        }
> +        avdevice_free_list_devices(&device_list);

This code can be factorized among input and output.

>         return AVERROR_EXIT;
>     }
> 
> @@ -400,4 +415,9 @@ int ff_decklink_write_packet(AVFormatContext *avctx, AVPacket *pkt)
>     return AVERROR(EIO);
> }
> 
> +int ff_decklink_list_output_devices(AVFormatContext *avctx, struct AVDeviceInfoList *device_list)
> +{
> +    return ff_decklink_list_devices(avctx, device_list, 0, 1);
> +}
> +
> } /* extern "C" */
> diff --git a/libavdevice/decklink_enc.h b/libavdevice/decklink_enc.h
> index 5ffc05cd68..39237673b4 100644
> --- a/libavdevice/decklink_enc.h
> +++ b/libavdevice/decklink_enc.h
> @@ -29,6 +29,7 @@ extern "C" {
> int ff_decklink_write_header(AVFormatContext *avctx);
> int ff_decklink_write_packet(AVFormatContext *avctx, AVPacket *pkt);
> int ff_decklink_write_trailer(AVFormatContext *avctx);
> +int ff_decklink_list_output_devices(AVFormatContext *avctx, struct AVDeviceInfoList *device_list);
> 
> #ifdef __cplusplus
> } /* extern "C" */
> diff --git a/libavdevice/decklink_enc_c.c b/libavdevice/decklink_enc_c.c
> index 03734f8507..360535cfda 100644
> --- a/libavdevice/decklink_enc_c.c
> +++ b/libavdevice/decklink_enc_c.c
> @@ -49,6 +49,7 @@ AVOutputFormat ff_decklink_muxer = {
>     .video_codec    = AV_CODEC_ID_WRAPPED_AVFRAME,
>     .subtitle_codec = AV_CODEC_ID_NONE,
>     .flags          = AVFMT_NOFILE,
> +    .get_device_list = ff_decklink_list_output_devices,
>     .priv_class     = &decklink_muxer_class,
>     .priv_data_size = sizeof(struct decklink_cctx),
>     .write_header   = ff_decklink_write_header,
> -- 
> 2.13.2
>

Regards,
Marton


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