> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf > Of Mark Thompson > Sent: Thursday, November 15, 2018 05:48 > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH v2] ffmpeg: Add option to force a > specific decode format > > On 14/11/18 01:35, Fu, Linjie wrote: > >> -----Original Message----- > >> From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On > Behalf > >> Of Mark Thompson > >> Sent: Wednesday, November 14, 2018 09:11 > >> To: ffmpeg-devel@ffmpeg.org > >> Subject: Re: [FFmpeg-devel] [PATCH v2] ffmpeg: Add option to force a > >> specific decode format > >> > >> On 14/11/18 00:50, Fu, Linjie wrote: > >>>> -----Original Message----- > >>>> From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On > >> Behalf > >>>> Of Mark Thompson > >>>> Sent: Wednesday, November 14, 2018 07:44 > >>>> To: ffmpeg-devel@ffmpeg.org > >>>> Subject: [FFmpeg-devel] [PATCH v2] ffmpeg: Add option to force a > >> specific > >>>> decode format > >>>> > >>>> Fixes #7519. > >>>> --- > >>>> doc/ffmpeg.texi | 13 ++++++++++++ > >>>> fftools/ffmpeg.c | 10 ++++++++++ > >>>> fftools/ffmpeg.h | 4 ++++ > >>>> fftools/ffmpeg_opt.c | 47 > >>>> ++++++++++++++++++++++++++++++++++++++++++++ > >>>> 4 files changed, 74 insertions(+) > >>>> > >>>> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi > >>>> index 3717f22d42..d127bc0f0d 100644 > >>>> --- a/doc/ffmpeg.texi > >>>> +++ b/doc/ffmpeg.texi > >>>> @@ -920,6 +920,19 @@ would be more efficient. > >>>> When doing stream copy, copy also non-key frames found at the > >>>> beginning. > >>>> > >>>> +@item -decode_format[:@var{stream_specifier}] > >>>> @var{pixfmt}[,@var{pixfmt}...] (@emph{input,per-stream}) > >>>> +Set the possible output formats to be used by the decoder for this > >> stream. > >>>> +If the decoder does not natively support any format in the given list > for > >>>> +the input stream then decoding will fail rather than continuing with a > >>>> +different format. > >>>> + > >>>> +In general this should not be set - the decoder will select an output > >>>> +format based on the input stream parameters and available > components, > >>>> and > >>>> +that will be automatically converted to whatever the output requires. > It > >>>> +may be useful to force a hardware decoder supporting output in > >> multiple > >>>> +different memory types to pick a desired one, or to ensure that a > >> hardware > >>>> +decoder is used when software fallback is also available. > >>>> + > >>>> @item -init_hw_device > >>>> @var{type}[=@var{name}][:@var{device}[,@var{key=value}...]] > >>>> Initialise a new hardware device of type @var{type} called > @var{name}, > >>>> using the > >>>> given device parameters. > >>>> diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c > >>>> index 38c21e944a..c651c8d3a8 100644 > >>>> --- a/fftools/ffmpeg.c > >>>> +++ b/fftools/ffmpeg.c > >>>> @@ -598,6 +598,7 @@ static void ffmpeg_cleanup(int ret) > >>>> avsubtitle_free(&ist->prev_sub.subtitle); > >>>> av_frame_free(&ist->sub2video.frame); > >>>> av_freep(&ist->filters); > >>>> + av_freep(&ist->decode_formats); > >>>> av_freep(&ist->hwaccel_device); > >>>> av_freep(&ist->dts_buffer); > >>>> > >>>> @@ -2800,6 +2801,15 @@ static enum AVPixelFormat > >>>> get_format(AVCodecContext *s, const enum AVPixelFormat > >>>> const AVCodecHWConfig *config = NULL; > >>>> int i; > >>>> > >>>> + if (ist->decode_formats) { > >>>> + for (i = 0; ist->decode_formats[i] != AV_PIX_FMT_NONE; i++) > >>>> { > >>>> + if (ist->decode_formats[i] == *p) > >>>> + break; > >>>> + } > >>>> + if (ist->decode_formats[i] != *p) > >>>> + continue; > >>>> + } > >>>> + > >>>> if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL)) > >>>> break; > >>>> > >>>> diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h > >>>> index eb1eaf6363..b06fd18b1c 100644 > >>>> --- a/fftools/ffmpeg.h > >>>> +++ b/fftools/ffmpeg.h > >>>> @@ -125,6 +125,8 @@ typedef struct OptionsContext { > >>>> int nb_ts_scale; > >>>> SpecifierOpt *dump_attachment; > >>>> int nb_dump_attachment; > >>>> + SpecifierOpt *decode_formats; > >>>> + int nb_decode_formats; > >>>> SpecifierOpt *hwaccels; > >>>> int nb_hwaccels; > >>>> SpecifierOpt *hwaccel_devices; > >>>> @@ -334,6 +336,8 @@ typedef struct InputStream { > >>>> int top_field_first; > >>>> int guess_layout_max; > >>>> > >>>> + enum AVPixelFormat *decode_formats; > >>>> + > >>>> int autorotate; > >>>> > >>>> int fix_sub_duration; > >>>> diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c > >>>> index d4851a2cd8..63bb05053b 100644 > >>>> --- a/fftools/ffmpeg_opt.c > >>>> +++ b/fftools/ffmpeg_opt.c > >>>> @@ -701,6 +701,7 @@ static void add_input_streams(OptionsContext > *o, > >>>> AVFormatContext *ic) > >>>> AVStream *st = ic->streams[i]; > >>>> AVCodecParameters *par = st->codecpar; > >>>> InputStream *ist = av_mallocz(sizeof(*ist)); > >>>> + char *decode_formats = NULL; > >>>> char *framerate = NULL, *hwaccel_device = NULL; > >>>> const char *hwaccel = NULL; > >>>> char *hwaccel_output_format = NULL; > >>>> @@ -797,6 +798,49 @@ static void add_input_streams(OptionsContext > >> *o, > >>>> AVFormatContext *ic) > >>>> ist->top_field_first = -1; > >>>> MATCH_PER_STREAM_OPT(top_field_first, i, > >>>> ist->top_field_first, > ic, > >>>> st); > >>>> > >>>> + MATCH_PER_STREAM_OPT(decode_formats, str, > >> decode_formats, ic, > >>>> st); > >>>> + if (decode_formats) { > >>>> + const char *p, *q; > >>>> + int i, nb_formats; > >>>> + char tmp[32]; > >>>> + > >>>> + nb_formats = 0; > >>>> + for (p = decode_formats; p; p = strchr(p + 1, ',')) > >>>> + ++nb_formats; > >>>> + > >>>> + ist->decode_formats = > >>>> + av_malloc_array(nb_formats + 1, sizeof(*ist- > >>> decode_formats)); > >>>> + if (!ist->decode_formats) > >>>> + exit_program(1); > >>>> + > >>>> + p = decode_formats; > >>>> + for (i = 0; i < nb_formats; i++) { > >>>> + q = strchr(p, ','); > >>>> + if (!q) { > >>>> + ist->decode_formats[i] = av_get_pix_fmt(p); > >>>> + if (ist->decode_formats[i] == AV_PIX_FMT_NONE) > >>>> + break; > >>>> + continue; > >>>> + } > >>>> + if (q - p > sizeof(tmp) - 1) > >>>> + break; > >>>> + memcpy(tmp, p, q - p); > >>>> + tmp[q - p] = 0; > >>>> + ist->decode_formats[i] = av_get_pix_fmt(tmp); > >>>> + if (ist->decode_formats[i] == AV_PIX_FMT_NONE) > >>>> + break; > >>>> + p = q + 1; > >>>> + } > >>>> + if (i < nb_formats) { > >>>> + av_log(NULL, AV_LOG_FATAL, > >>>> + "Unrecognised decode format: %s.\n", p); > >>>> + exit_program(1); > >>>> + } > >>>> + ist->decode_formats[nb_formats] = AV_PIX_FMT_NONE; > >>>> + } else { > >>>> + ist->decode_formats = NULL; > >>>> + } > >>>> + > >>>> MATCH_PER_STREAM_OPT(hwaccels, str, hwaccel, ic, st); > >>>> if (hwaccel) { > >>>> // The NVDEC hwaccels use a CUDA device, so remap the > name > >> here. > >>>> @@ -3583,6 +3627,9 @@ const OptionDef options[] = { > >>>> "audio bitrate (please use -b:a)", "bitrate" }, > >>>> { "b", OPT_VIDEO | HAS_ARG | OPT_PERFILE | OPT_OUTPUT, > >>>> { .func_arg = opt_bitrate }, > >>>> "video bitrate (please use -b:v)", "bitrate" }, > >>>> + { "decode_format", OPT_VIDEO | OPT_STRING | HAS_ARG | > >>>> OPT_EXPERT | > >>>> + OPT_SPEC | OPT_INPUT, > >>>> { .off = > >>>> OFFSET(decode_formats) }, > >>>> + "set output format(s) to be used by decoder, fail if none of > >>>> these > >>>> formats are available", "format" }, > >>>> { "hwaccel", OPT_VIDEO | OPT_STRING | HAS_ARG | > OPT_EXPERT > >> | > >>>> OPT_SPEC | OPT_INPUT, > >>>> { .off = > >>>> OFFSET(hwaccels) }, > >>>> "use HW accelerated decoding", "hwaccel name" }, > >>>> -- > >>>> 2.19.1 > >>>> > >>> > >>> Is there any other conditions which will cause the hwaccel failed and > >> fallback to software path? > >>> Like profile was not supported by hardware? > >> > >> If this option is set then get_format will never choose a format not on the > list > >> you provide, so it shouldn't be able to use software decode unless a > >> software format is on the list. > >> > >>> I applied the patch and tested some cases, like yuv422 VAAPI decoding > >> (currently not supported), HEVC decoding with unsupported profile. > >>> It reports an error like "hwaccel initialization returned error", and > continue > >> to decode and produce less frames than expected. (which I thought > fallback > >> still happened). > >> > >> Can you give an example? With -v debug there will be output saying > exactly > >> what happened in ff_get_format(). > >> > >> - Mark > > > > > > Got information like this: > > > > [hevc @ 0x55b87457dbc0] Unknown HEVC profile: 0 > > [hevc @ 0x55b87457dbc0] Decoding SPS > > [hevc @ 0x55b87457dbc0] Unknown HEVC profile: 0 > > [hevc @ 0x55b87457dbc0] Decoding PPS > > [hevc @ 0x55b87457dbc0] Format vaapi_vld chosen by get_format(). > > [hevc @ 0x55b87457dbc0] Format vaapi_vld requires hwaccel initialisation. > > [hevc @ 0x55b87457dbc0] Codec hevc profile 0 not supported for hardware > decode. > > [hevc @ 0x55b87457dbc0] Failed setup for format vaapi_vld: hwaccel > initialisation returned error. > > [hevc @ 0x55b87457dbc0] Format vaapi_vld not usable, retrying > get_format() without it. > > [hevc @ 0x55b87457dbc0] Error parsing NAL unit #3. > > cur_dts is invalid (this is harmless if it occurs once at the start per > > stream) > > [hevc @ 0x55b87458b7c0] nal_unit_type: 1(TRAIL_R), nuh_layer_id: 0, > temporal_id: 0 > > [hevc @ 0x55b87458b7c0] Could not find ref with POC 0 > > > > See the attached report file for more details. > > This is a decoder bug - get_format() is not correctly called again after it > fails, > and the decoder then uses the software pixfmt derived from the SPS on > subsequent frames. > > (I did pretty much all of my testing with H.264, which does not have this > problem.) > Works for me on forcing hwaccel in HEVC vaapi decoding after applying the hevcdec patch. Thanks for answering my questions.
- Linjie _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
