[FFmpeg-devel] [PATCH] ffprobe: add -framecount option.

[Clément Bœsch]

Hi,

Some information might not be available until we loop over all the
packets, and the number of frames is among them. This patch add the
possibility to run a slow analysis in order to get that value.

This really is a "violent" method, slow, and not really sexy (I don't like
the seek I have to do for instance), but it might be useful for various
reasons.

Any better idea is welcome,

Regards,

-- 
Clément B.
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From 8cd400bd3d56139fc78b2ebd1e6b0d98a3952858 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20B=C5=93sch?= <clement.boesch at smartjog.com>
Date: Mon, 3 Oct 2011 17:54:40 +0200
Subject: [PATCH] ffprobe: add -framecount option.

---
 doc/ffprobe.texi |   17 +++++++++++++++++
 ffprobe.c        |   25 +++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/doc/ffprobe.texi b/doc/ffprobe.texi
index a5d5df8..1504652 100644
--- a/doc/ffprobe.texi
+++ b/doc/ffprobe.texi
@@ -112,6 +112,23 @@ multimedia stream.
 Each media stream information is printed within a dedicated section
 with name "STREAM".
 
+ at item -framecount @var{mode}
+Advanced frame count.
+Available modes are:
+
+ at table @option
+ at item default
+Only print nb_frames if available.
+
+ at item soft
+Count each video frame if nb_frames is not available, and print them under the
+key exact_nb_frames. Also print exact_nb_key_frames. This operation is slow.
+
+ at item hard
+Whatever the value of nb_frames, exact_nb_frames and exact_nb_key_frames will
+be computed and printed. Just like soft, this operation is slow.
+ at end table
+
 @item -i @var{input_file}
 Read @var{input_file}.
 
diff --git a/ffprobe.c b/ffprobe.c
index 2c354ad..135e204 100644
--- a/ffprobe.c
+++ b/ffprobe.c
@@ -41,6 +41,7 @@ static int use_value_prefix             = 0;
 static int use_byte_value_binary_prefix = 0;
 static int use_value_sexagesimal_format = 0;
 
+static char *framecount;
 static char *print_format;
 
 static const OptionDef options[];
@@ -439,6 +440,29 @@ static void show_stream(struct writer *w, AVFormatContext *fmt_ctx, int stream_i
     if (stream->nb_frames)
         print_fmt("nb_frames", "%"PRId64, stream->nb_frames);
 
+    if (fmt_ctx->pb->seekable &&
+         stream->codec && stream->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
+        (strcmp(framecount, "hard") == 0 ||
+        (strcmp(framecount, "soft") == 0 && stream->nb_frames == 0))) {
+        AVPacket pkt;
+        int64_t nb_frames = 0, nb_key_frames = 0;
+
+        av_init_packet(&pkt);
+        while (av_read_frame(fmt_ctx, &pkt) >= 0) {
+            if (pkt.stream_index == stream_idx) {
+                nb_frames++;
+                nb_key_frames += pkt.flags & AV_PKT_FLAG_KEY;
+            }
+            av_free_packet(&pkt);
+        }
+        print_fmt("exact_nb_frames",     "%"PRId64, nb_frames);
+        print_fmt("exact_nb_key_frames", "%"PRId64, nb_key_frames);
+
+        if (av_seek_frame(fmt_ctx, stream_idx, 0, AVSEEK_FLAG_BYTE) < 0)
+            av_seek_frame(fmt_ctx, stream_idx, 0, AVSEEK_FLAG_BACKWARD);
+    }
+
+
     w->show_tags(w, stream->metadata);
 
     w->print_footer("STREAM");
@@ -660,6 +684,7 @@ static const OptionDef options[] = {
     { "show_format",  OPT_BOOL, {(void*)&do_show_format} , "show format/container info" },
     { "show_packets", OPT_BOOL, {(void*)&do_show_packets}, "show packets info" },
     { "show_streams", OPT_BOOL, {(void*)&do_show_streams}, "show streams info" },
+    { "framecount", OPT_STRING | HAS_ARG, {(void*)&framecount}, "advanced frame count (available modes are: default, soft, hard)", "mode" },
     { "default", HAS_ARG | OPT_AUDIO | OPT_VIDEO | OPT_EXPERT, {(void*)opt_default}, "generic catch all option", "" },
     { "i", HAS_ARG, {(void *)opt_input_file}, "read specified file", "input_file"},
     { NULL, },
-- 
1.7.5.4

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