X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavformat%2Fmp3dec.c;h=007c6eaf8bd2a314f0e68ba6e8e2af49d3aca051;hb=385eb066ce8c4be42a3f1d8c390137499cb35dd5;hp=ff794ff277731584cd9319b43956909d088dd5a9;hpb=eb823df817660947fe9c8172f01319c3b972b588;p=ffmpeg

diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
index ff794ff2777..007c6eaf8bd 100644
--- a/libavformat/mp3dec.c
+++ b/libavformat/mp3dec.c
@@ -54,7 +54,7 @@ typedef struct {
     int is_cbr;
 } MP3DecContext;
 
-static int check(AVFormatContext *s, int64_t pos);
+static int check(AVIOContext *pb, int64_t pos);
 
 /* mp3 read */
 
@@ -98,7 +98,7 @@ static int mp3_read_probe(AVProbeData *p)
     avcodec_free_context(&avctx);
     // keep this in sync with ac3 probe, both need to avoid
     // issues with MPEG-files!
-    if   (first_frames>=4) return AVPROBE_SCORE_EXTENSION + 1;
+    if   (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1;
     else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;
     else if(max_frames>=4 && max_frames >= p->buf_size/10000) return AVPROBE_SCORE_EXTENSION / 2;
     else if(ff_id3v2_match(buf0, ID3v2_DEFAULT_MAGIC) && 2*ff_id3v2_tag_len(buf0) >= p->buf_size)
@@ -376,7 +376,7 @@ static int mp3_read_header(AVFormatContext *s)
     for (i = 0; i < 64 * 1024; i++) {
         if (!(i&1023))
             ffio_ensure_seekback(s->pb, i + 1024 + 4);
-        if (check(s, off + i) >= 0) {
+        if (check(s->pb, off + i) >= 0) {
             av_log(s, AV_LOG_INFO, "Skipping %d bytes of junk at %"PRId64".\n", i, off);
             avio_seek(s->pb, off + i, SEEK_SET);
             break;
@@ -418,64 +418,42 @@ static int mp3_read_packet(AVFormatContext *s, AVPacket *pkt)
     return ret;
 }
 
-static int check(AVFormatContext *s, int64_t pos)
+#define SEEK_WINDOW 4096
+
+static int check(AVIOContext *pb, int64_t pos)
 {
-    int64_t ret = avio_seek(s->pb, pos, SEEK_SET);
+    int64_t ret = avio_seek(pb, pos, SEEK_SET);
     unsigned header;
     MPADecodeHeader sd;
     if (ret < 0)
         return ret;
-    header = avio_rb32(s->pb);
+
+    header = avio_rb32(pb);
     if (ff_mpa_check_header(header) < 0)
         return -1;
     if (avpriv_mpegaudio_decode_header(&sd, header) == 1)
         return -1;
+
     return sd.frame_size;
 }
 
-static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
-                    int flags)
+static int64_t mp3_sync(AVFormatContext *s, int64_t target_pos, int flags)
 {
-    MP3DecContext *mp3 = s->priv_data;
-    AVIndexEntry *ie, ie1;
-    AVStream *st = s->streams[0];
-    int64_t ret  = av_index_search_timestamp(st, timestamp, flags);
-    int i, j;
     int dir = (flags&AVSEEK_FLAG_BACKWARD) ? -1 : 1;
     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)
-        && st->duration > 0
-        && mp3->header_filesize > s->internal->data_offset
-        && mp3->frames) {
-        ie = &ie1;
-        timestamp = av_clip64(timestamp, 0, st->duration);
-        ie->timestamp = timestamp;
-        ie->pos       = av_rescale(timestamp, mp3->header_filesize, st->duration) + s->internal->data_offset;
-    } else if (mp3->xing_toc) {
-        if (ret < 0)
-            return ret;
-
-        ie = &st->index_entries[ret];
-    } else {
-        return -1;
-    }
+    int best_score, i, j;
+    int64_t ret;
 
-    avio_seek(s->pb, FFMAX(ie->pos - 4096, 0), SEEK_SET);
-    ret = avio_seek(s->pb, ie->pos, SEEK_SET);
+    avio_seek(s->pb, FFMAX(target_pos - SEEK_WINDOW, 0), SEEK_SET);
+    ret = avio_seek(s->pb, target_pos, SEEK_SET);
     if (ret < 0)
         return ret;
 
 #define MIN_VALID 3
-    best_pos = ie->pos;
+    best_pos = target_pos;
     best_score = 999;
-    for(i=0; i<4096; i++) {
-        int64_t pos = ie->pos + (dir > 0 ? i - 1024 : -i);
+    for(i=0; i<SEEK_WINDOW; i++) {
+        int64_t pos = target_pos + (dir > 0 ? i - SEEK_WINDOW/4 : -i);
         int64_t candidate = -1;
         int score = 999;
 
@@ -483,10 +461,10 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
             continue;
 
         for(j=0; j<MIN_VALID; j++) {
-            ret = check(s, pos);
+            ret = check(s->pb, pos);
             if(ret < 0)
                 break;
-            if ((ie->pos - pos)*dir <= 0 && abs(MIN_VALID/2-j) < score) {
+            if ((target_pos - pos)*dir <= 0 && abs(MIN_VALID/2-j) < score) {
                 candidate = pos;
                 score = abs(MIN_VALID/2-j);
             }
@@ -500,9 +478,42 @@ static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
         }
     }
 
-    ret = avio_seek(s->pb, best_pos, SEEK_SET);
-    if (ret < 0)
-        return ret;
+    return avio_seek(s->pb, best_pos, SEEK_SET);
+}
+
+static int mp3_seek(AVFormatContext *s, int stream_index, int64_t timestamp,
+                    int flags)
+{
+    MP3DecContext *mp3 = s->priv_data;
+    AVIndexEntry *ie, ie1;
+    AVStream *st = s->streams[0];
+    int64_t ret  = av_index_search_timestamp(st, timestamp, flags);
+    int64_t best_pos;
+
+    if (mp3->usetoc == 2)
+        return -1; // generic index code
+
+    if (   mp3->is_cbr
+        && (mp3->usetoc == 0 || !mp3->xing_toc)
+        && st->duration > 0
+        && mp3->header_filesize > s->internal->data_offset
+        && mp3->frames) {
+        ie = &ie1;
+        timestamp = av_clip64(timestamp, 0, st->duration);
+        ie->timestamp = timestamp;
+        ie->pos       = av_rescale(timestamp, mp3->header_filesize, st->duration) + s->internal->data_offset;
+    } else if (mp3->xing_toc) {
+        if (ret < 0)
+            return ret;
+
+        ie = &st->index_entries[ret];
+    } else {
+        return -1;
+    }
+
+    best_pos = mp3_sync(s, ie->pos, flags);
+    if (best_pos < 0)
+        return best_pos;
 
     if (mp3->is_cbr && ie == &ie1) {
         int frame_duration = av_rescale(st->duration, 1, mp3->frames);