[FFmpeg-devel] [PATCH 3/5] avformat/mp3dec: allow enabling generic seek mode

[wm4]

"-usetoc 2" now invokes the generic seek and indexing mode. This mode
skips data until the seek target is reached, and this is exact. It also
makes gapless audio actually work if a seek past the start of the file
is involved.
---
Strange option value. On the other hand, it will be made default, so
this option will generally be used only to select the "old" seek modes.
But in general, libavformat should probably have something to switch
between slow/accurate and fast/inaccurate seeking.
---
 libavformat/mp3dec.c           | 12 +++++++++---
 tests/fate/gapless.mak         |  5 +++--
 tests/ref/fate/gapless-mp3     |  5 -----
 tests/ref/fate/gapless-mp3-cbr |  5 +++++
 4 files changed, 17 insertions(+), 10 deletions(-)
 delete mode 100644 tests/ref/fate/gapless-mp3
 create mode 100644 tests/ref/fate/gapless-mp3-cbr

diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index 008cb23..8a4dfbd 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -110,7 +110,7 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration
 {
     int i;
     MP3DecContext *mp3 = s->priv_data;
-    int fill_index = mp3->usetoc && duration > 0;
+    int fill_index = mp3->usetoc == 1 && duration > 0;
 
     if (!filesize &&
         !(filesize = avio_size(s->pb))) {
@@ -336,6 +336,9 @@ static int mp3_read_header(AVFormatContext *s)
     int ret;
     int i;
 
+    if (mp3->usetoc < 0)
+        mp3->usetoc = 0;
+
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
@@ -432,8 +435,11 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
     int64_t best_pos;
     int best_score;
 
+    if (mp3->usetoc == 2)
+        return -1; // generic index code
+
     if (   mp3->is_cbr
-        && (mp3->usetoc <= 0 || !mp3->xing_toc)
+        && (mp3->usetoc == 0 || !mp3->xing_toc)
         && st->duration > 0
         && mp3->header_filesize > s->internal->data_offset
         && mp3->frames) {
@@ -498,7 +504,7 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
 }
 
 static const AVOption options[] = {
-    { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, AV_OPT_FLAG_DECODING_PARAM},
+    { "usetoc", "use table of contents", offsetof(MP3DecContext, usetoc), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 2, AV_OPT_FLAG_DECODING_PARAM},
     { NULL },
 };
 
diff --git a/tests/fate/gapless.mak b/tests/fate/gapless.mak
index a09dac6..6860d74 100644
--- a/tests/fate/gapless.mak
+++ b/tests/fate/gapless.mak
@@ -1,5 +1,6 @@
-FATE_GAPLESS-$(CONFIG_MP3_DEMUXER) += fate-gapless-mp3 fate-gapless-mp3-notoc
-fate-gapless-mp3: CMD = gapless $(TARGET_SAMPLES)/gapless/gapless.mp3 "-usetoc 1"
+FATE_GAPLESS-$(CONFIG_MP3_DEMUXER) += fate-gapless-mp3 fate-gapless-mp3-cbr fate-gapless-mp3-notoc
+fate-gapless-mp3: CMD = gapless $(TARGET_SAMPLES)/gapless/gapless.mp3 "-usetoc 2"
+fate-gapless-mp3-cbr: CMD = gapless $(TARGET_SAMPLES)/gapless/gapless.mp3 "-usetoc 1"
 fate-gapless-mp3-notoc: CMD = gapless $(TARGET_SAMPLES)/gapless/gapless.mp3 "-usetoc 0"
 
 FATE_GAPLESS = $(FATE_GAPLESS-yes)
diff --git a/tests/ref/fate/gapless-mp3 b/tests/ref/fate/gapless-mp3
deleted file mode 100644
index 984ae84..0000000
--- a/tests/ref/fate/gapless-mp3
+++ /dev/null
@@ -1,5 +0,0 @@
-d5c88cf38416329a052a9b0cb140fb4c *tests/data/fate/gapless-mp3.out-1
-c96c3ae7bd3300fd2f4debac222de5b7
-3386bc2009b31b7ef39247918cbb02a5 *tests/data/fate/gapless-mp3.out-2
-c96c3ae7bd3300fd2f4debac222de5b7
-70e7cd7f2b6365e7f48ed206113f06fc *tests/data/fate/gapless-mp3.out-3
diff --git a/tests/ref/fate/gapless-mp3-cbr b/tests/ref/fate/gapless-mp3-cbr
new file mode 100644
index 0000000..7ecc328
--- /dev/null
+++ b/tests/ref/fate/gapless-mp3-cbr
@@ -0,0 +1,5 @@
+d5c88cf38416329a052a9b0cb140fb4c *tests/data/fate/gapless-mp3-cbr.out-1
+c96c3ae7bd3300fd2f4debac222de5b7
+3386bc2009b31b7ef39247918cbb02a5 *tests/data/fate/gapless-mp3-cbr.out-2
+c96c3ae7bd3300fd2f4debac222de5b7
+70e7cd7f2b6365e7f48ed206113f06fc *tests/data/fate/gapless-mp3-cbr.out-3
-- 
2.1.4