[FFmpeg-devel] [PATCH]lavc/amrwbdec: Do not ignore NO_DATA frames

[Carl Eugen Hoyos]

Am So., 5. Apr. 2020 um 17:10 Uhr schrieb James Almer <jamrial at gmail.com>:
>
> On 4/5/2020 12:07 PM, Carl Eugen Hoyos wrote:
> > Am So., 5. Apr. 2020 um 16:45 Uhr schrieb James Almer <jamrial at gmail.com>:
> >>
> >> On 1/30/2019 10:47 AM, Carl Eugen Hoyos wrote:
> >>> 2019-01-29 22:47 GMT+01:00, Carl Eugen Hoyos <ceffmpeg at gmail.com>:
> >>>> Hi!
> >>>>
> >>>> Attached patch fixes decoding NO_DATA amr-wb frames.
> >>>
> >>> Now with patch.
> >>>
> >>> Carl Eugen
> >>
> >>> From 0a8c318c49ec358ad646ed601588154cf7d7da37 Mon Sep 17 00:00:00 2001
> >>> From: Carl Eugen Hoyos <ceffmpeg at gmail.com>
> >>> Date: Tue, 29 Jan 2019 22:46:37 +0100
> >>> Subject: [PATCH] lavc/amrwbdec: Do not ignore NO_DATA frames.
> >>>
> >>> Fixes the actual output duration of the sample in ticket #7113.
> >>> ---
> >>>  libavcodec/amrwbdata.h |    2 +-
> >>>  libavcodec/amrwbdec.c  |    9 ++++++++-
> >>>  2 files changed, 9 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/libavcodec/amrwbdata.h b/libavcodec/amrwbdata.h
> >>> index 8a8cbfd..95c0aaa 100644
> >>> --- a/libavcodec/amrwbdata.h
> >>> +++ b/libavcodec/amrwbdata.h
> >>> @@ -1884,7 +1884,7 @@ static const float lpf_7_coef[31] = { // low pass, 7kHz cutoff
> >>>  /** Core frame sizes in each mode */
> >>>  static const uint16_t cf_sizes_wb[] = {
> >>>      132, 177, 253, 285, 317, 365, 397, 461, 477,
> >>> -    40 /// SID/comfort noise frame
> >>> +    40, 0, 0, 0, 0, 0, 0
> >>>  };
> >>>
> >>>  #endif /* AVCODEC_AMRWBDATA_H */
> >>> diff --git a/libavcodec/amrwbdec.c b/libavcodec/amrwbdec.c
> >>> index 47fe7eb..b488a5d 100644
> >>> --- a/libavcodec/amrwbdec.c
> >>> +++ b/libavcodec/amrwbdec.c
> >>> @@ -1119,12 +1119,19 @@ static int amrwb_decode_frame(AVCodecContext *avctx, void *data,
> >>>      buf_out = (float *)frame->data[0];
> >>>
> >>>      header_size      = decode_mime_header(ctx, buf);
> >>> +    expected_fr_size = ((cf_sizes_wb[ctx->fr_cur_mode] + 7) >> 3) + 1;
> >>> +
> >>> +    if (ctx->fr_cur_mode == NO_DATA) {
> >>> +        for (i = 0; i < frame->nb_samples; i++)
> >>> +            buf_out[i] = 0.f;
> >>
> >> You can use av_samples_set_silence() for this.
> >
> > (Is memset(0) valid for floats?)
>
> I would hope so, considering this function is used in half a dozen
> filters, and the core encoding lavc code...

=-)

Is the patch ok?

Carl Eugen