[FFmpeg-devel] [PATCH] ffplay: add startup volume option

[Ganesh Ajjanagadde]

24.12.2016, 20:00, "Marton Balint" <cus at passwd.hu>:
> On Thu, 22 Dec 2016, gajjanag at yandex.com wrote:
>
>>  From: Ganesh Ajjanagadde <gajjanag at alum.mit.edu>
>>
>>  Fixes Ticket 5389.
>>
>>  Signed-off-by: Ganesh Ajjanagadde <gajjanag at alum.mit.edu>
>>  ---
>>  doc/ffplay.texi | 4 ++++
>>  ffplay.c | 10 +++++++++-
>>  2 files changed, 13 insertions(+), 1 deletion(-)
>>
>>  diff --git a/doc/ffplay.texi b/doc/ffplay.texi
>>  index 073b457256..378a229d67 100644
>>  --- a/doc/ffplay.texi
>>  +++ b/doc/ffplay.texi
>>  @@ -62,6 +62,10 @@ see @ref{time duration syntax,,the Time duration section in the ffmpeg-utils(1)
>>  Seek by bytes.
>>  @item -nodisp
>>  Disable graphical display.
>>  + at item -volume
>>  +Set the startup volume. 0 means silence, 100 means no volume reduction or
>>  +amplification. Negative values are treated as 0, values above 100 are treated
>>  +as 100.
>>  @item -f @var{fmt}
>>  Force format.
>>  @item -window_title @var{title}
>>  diff --git a/ffplay.c b/ffplay.c
>>  index 911fd7f947..de603c0a27 100644
>>  --- a/ffplay.c
>>  +++ b/ffplay.c
>>  @@ -322,6 +322,7 @@ static int subtitle_disable;
>>  static const char* wanted_stream_spec[AVMEDIA_TYPE_NB] = {0};
>>  static int seek_by_bytes = -1;
>>  static int display_disable;
>>  +static int startup_volume = 100;
>>  static int show_status = 1;
>>  static int av_sync_type = AV_SYNC_AUDIO_MASTER;
>>  static int64_t start_time = AV_NOPTS_VALUE;
>>  @@ -3105,7 +3106,13 @@ static VideoState *stream_open(const char *filename, AVInputFormat *iformat)
>>      init_clock(&is->audclk, &is->audioq.serial);
>>      init_clock(&is->extclk, &is->extclk.serial);
>>      is->audio_clock_serial = -1;
>>  - is->audio_volume = SDL_MIX_MAXVOLUME;
>>  + if (startup_volume < 0)
>>  + av_log(NULL, AV_LOG_WARNING, "-volume=%d < 0, setting to 0\n", startup_volume);
>>  + if (startup_volume > 100)
>>  + av_log(NULL, AV_LOG_WARNING, "-volume=%d > 100, setting to 100\n", startup_volume);
>>  + startup_volume = av_clip(startup_volume, 0, 100);
>>  + startup_volume = av_clip(SDL_MIX_MAXVOLUME * startup_volume / 100.0, 0, SDL_MIX_MAXVOLUME);
>
> Any reason you use 100.0 here instead of a simple integer (100)?

Nothing really, I assumed (incorrectly) that double to int cast does rounding instead of truncation,
which happens with integer division.
On the other hand, the difference here between rounding and truncation is < 1%.
Whatever you prefer, i.e can lrint it to get better rounding, or change to 100 and not bother.

>
>>  + is->audio_volume = startup_volume;
>>      is->muted = 0;
>>      is->av_sync_type = av_sync_type;
>>      is->read_tid = SDL_CreateThread(read_thread, "read_thread", is);
>>  @@ -3586,6 +3593,7 @@ static const OptionDef options[] = {
>>      { "t", HAS_ARG, { .func_arg = opt_duration }, "play \"duration\" seconds of audio/video", "duration" },
>>      { "bytes", OPT_INT | HAS_ARG, { &seek_by_bytes }, "seek by bytes 0=off 1=on -1=auto", "val" },
>>      { "nodisp", OPT_BOOL, { &display_disable }, "disable graphical display" },
>>  + { "volume", OPT_INT | HAS_ARG, { &startup_volume}, "set startup volume 0=min 100=max", "volume" },
>>      { "f", HAS_ARG, { .func_arg = opt_format }, "force format", "fmt" },
>>      { "pix_fmt", HAS_ARG | OPT_EXPERT | OPT_VIDEO, { .func_arg = opt_frame_pix_fmt }, "set pixel format", "format" },
>>      { "stats", OPT_BOOL | OPT_EXPERT, { &show_status }, "show status", "" },
>>  --
>>  2.11.0
>
> Otherwise LGTM, thanks.
>
> Marton
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