> -----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. Thanks, - Linjie
ffmpeg-20181114-092556.log
Description: ffmpeg-20181114-092556.log
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