[FFmpeg-devel] [PATCH v2] ffmpeg: Add option to force a specific decode format
Mark Thompson
sw at jkqxz.net
Wed Nov 14 01:43:31 EET 2018
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.
+ at item -decode_format[:@var{stream_specifier}] @var{pixfmt}[, at 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}[, at 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
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