1 files changed, 188 insertions, 49 deletions

diff --git a/libavformat/srtdec.c b/libavformat/srtdec.c
index 9db5133a21..6113f70562 100644
--- a/libavformat/srtdec.c
+++ b/libavformat/srtdec.c
@@ -1,102 +1,241 @@
 /*
  * SubRip subtitle demuxer
  * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
+ * Copyright (c) 2015  Clément Bœsch <u pkh me>
  *
- * This file is part of Libav.
+ * This file is part of FFmpeg.
  *
- * Libav is free software; you can redistribute it and/or
+ * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * Libav is distributed in the hope that it will be useful,
+ * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with Libav; if not, write to the Free Software
+ * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avformat.h"
 #include "internal.h"
+#include "subtitles.h"
+#include "libavutil/bprint.h"
 #include "libavutil/intreadwrite.h"
 
+typedef struct {
+    FFDemuxSubtitlesQueue q;
+} SRTContext;
+
 static int srt_probe(AVProbeData *p)
 {
-    unsigned char *ptr = p->buf;
-    int i, v, num = 0;
+    int v;
+    char buf[64], *pbuf;
+    FFTextReader tr;
+
+    ff_text_init_buf(&tr, p->buf, p->buf_size);
+
+    while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
+        ff_text_r8(&tr);
+
+    /* Check if the first non-empty line is a number. We do not check what the
+     * number is because in practice it can be anything.
+     * Also, that number can be followed by random garbage, so we can not
+     * unfortunately check that we only have a number. */
+    if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0 ||
+        strtol(buf, &pbuf, 10) < 0 || pbuf == buf)
+        return 0;
+
+    /* Check if the next line matches a SRT timestamp */
+    if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
+        return 0;
+    if (buf[0] >= '0' && buf[0] <= '9' && strstr(buf, " --> ")
+        && sscanf(buf, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
+        return AVPROBE_SCORE_MAX;
+
+    return 0;
+}
+
+struct event_info {
+    int32_t x1, x2, y1, y2;
+    int duration;
+    int64_t pts;
+    int64_t pos;
+};
+
+static int get_event_info(const char *line, struct event_info *ei)
+{
+    int hh1, mm1, ss1, ms1;
+    int hh2, mm2, ss2, ms2;
+
+    ei->x1 = ei->x2 = ei->y1 = ei->y2 = ei->duration = -1;
+    ei->pts = AV_NOPTS_VALUE;
+    ei->pos = -1;
+    if (sscanf(line, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
+               "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
+               &hh1, &mm1, &ss1, &ms1,
+               &hh2, &mm2, &ss2, &ms2,
+               &ei->x1, &ei->x2, &ei->y1, &ei->y2) >= 8) {
+        const int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
+        const int64_t end   = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
+        ei->duration = end - start;
+        ei->pts = start;
+        return 0;
+    }
+    return -1;
+}
+
+static int add_event(FFDemuxSubtitlesQueue *q, AVBPrint *buf, char *line_cache,
+                     const struct event_info *ei, int append_cache)
+{
+    if (append_cache && line_cache[0])
+        av_bprintf(buf, "%s\n", line_cache);
+    line_cache[0] = 0;
 
-    if (AV_RB24(ptr) == 0xEFBBBF)
-        ptr += 3;  /* skip UTF-8 BOM */
+    while (buf->len > 0 && buf->str[buf->len - 1] == '\n')
+        buf->str[--buf->len] = 0;
 
-    for (i=0; i<2; i++) {
-        if (num == i && sscanf(ptr, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
-            return AVPROBE_SCORE_MAX;
-        num = atoi(ptr);
-        ptr += strcspn(ptr, "\n") + 1;
+    if (buf->len) {
+        AVPacket *sub = ff_subtitles_queue_insert(q, buf->str, buf->len, 0);
+        if (!sub)
+            return AVERROR(ENOMEM);
+        av_bprint_clear(buf);
+        sub->pos = ei->pos;
+        sub->pts = ei->pts;
+        sub->duration = ei->duration;
+        if (ei->x1 != -1) {
+            uint8_t *p = av_packet_new_side_data(sub, AV_PKT_DATA_SUBTITLE_POSITION, 16);
+            if (p) {
+                AV_WL32(p,      ei->x1);
+                AV_WL32(p +  4, ei->y1);
+                AV_WL32(p +  8, ei->x2);
+                AV_WL32(p + 12, ei->y2);
+            }
+        }
     }
+
     return 0;
 }
 
 static int srt_read_header(AVFormatContext *s)
 {
+    SRTContext *srt = s->priv_data;
+    AVBPrint buf;
     AVStream *st = avformat_new_stream(s, NULL);
+    int res = 0;
+    char line[4096], line_cache[4096];
+    int has_event_info = 0;
+    struct event_info ei;
+    FFTextReader tr;
+    ff_text_init_avio(s, &tr, s->pb);
+
     if (!st)
-        return -1;
+        return AVERROR(ENOMEM);
     avpriv_set_pts_info(st, 64, 1, 1000);
     st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
-    st->codec->codec_id   = AV_CODEC_ID_SRT;
-    return 0;
-}
+    st->codec->codec_id   = AV_CODEC_ID_SUBRIP;
 
-static int64_t get_pts(const char *buf)
-{
-    int i, v, hour, min, sec, hsec;
-
-    for (i=0; i<2; i++) {
-        if (sscanf(buf, "%d:%2d:%2d%*1[,.]%3d --> %*d:%*2d:%*2d%*1[,.]%3d",
-                   &hour, &min, &sec, &hsec, &v) == 5) {
-            min += 60*hour;
-            sec += 60*min;
-            return sec*1000+hsec;
+    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
+
+    line_cache[0] = 0;
+
+    while (!ff_text_eof(&tr)) {
+        struct event_info tmp_ei;
+        const int64_t pos = ff_text_pos(&tr);
+        ptrdiff_t len = ff_subtitles_read_line(&tr, line, sizeof(line));
+
+        if (len < 0)
+            break;
+
+        if (!len || !line[0])
+            continue;
+
+        if (get_event_info(line, &tmp_ei) < 0) {
+            char *pline;
+
+            if (!has_event_info)
+                continue;
+
+            if (line_cache[0]) {
+                /* We got some cache and a new line so we assume the cached
+                 * line was actually part of the payload */
+                av_bprintf(&buf, "%s\n", line_cache);
+                line_cache[0] = 0;
+            }
+
+            /* If the line doesn't start with a number, we assume it's part of
+             * the payload, otherwise is likely an event number preceding the
+             * timing information... but we can't be sure of this yet, so we
+             * cache it */
+            if (strtol(line, &pline, 10) < 0 || line == pline)
+                av_bprintf(&buf, "%s\n", line);
+            else
+                strcpy(line_cache, line);
+        } else {
+            if (has_event_info) {
+                /* We have the information of previous event, append it to the
+                 * queue. We insert the cached line if and only if the payload
+                 * is empty and the cached line is not a standalone number. */
+                char *pline = NULL;
+                const int standalone_number = strtol(line_cache, &pline, 10) >= 0 && pline && !*pline;
+                res = add_event(&srt->q, &buf, line_cache, &ei, !buf.len && !standalone_number);
+                if (res < 0)
+                    goto end;
+            } else {
+                has_event_info = 1;
+            }
+            tmp_ei.pos = pos;
+            ei = tmp_ei;
         }
-        buf += strcspn(buf, "\n") + 1;
     }
-    return AV_NOPTS_VALUE;
+
+    /* Append the last event. Here we force the cache to be flushed, because a
+     * trailing number is more likely to be geniune (for example a copyright
+     * date) and not the event index of an inexistant event */
+    if (has_event_info) {
+        res = add_event(&srt->q, &buf, line_cache, &ei, 1);
+        if (res < 0)
+            goto end;
+    }
+
+    ff_subtitles_queue_finalize(s, &srt->q);
+
+end:
+    av_bprint_finalize(&buf, NULL);
+    return res;
 }
 
-static inline int is_eol(char c)
+static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
-    return c == '\r' || c == '\n';
+    SRTContext *srt = s->priv_data;
+    return ff_subtitles_queue_read_packet(&srt->q, pkt);
 }
 
-static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
+static int srt_read_seek(AVFormatContext *s, int stream_index,
+                         int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
 {
-    char buffer[2048], *ptr = buffer, *ptr2;
-    int64_t pos = avio_tell(s->pb);
-    int res = AVERROR_EOF;
-
-    do {
-        ptr2 = ptr;
-        ptr += ff_get_line(s->pb, ptr, sizeof(buffer)+buffer-ptr);
-    } while (!is_eol(*ptr2) && !s->pb->eof_reached && ptr-buffer<sizeof(buffer)-1);
-
-    if (buffer[0] && !(res = av_new_packet(pkt, ptr-buffer))) {
-        memcpy(pkt->data, buffer, pkt->size);
-        pkt->flags |= AV_PKT_FLAG_KEY;
-        pkt->pos = pos;
-        pkt->pts = pkt->dts = get_pts(pkt->data);
-    }
-    return res;
+    SRTContext *srt = s->priv_data;
+    return ff_subtitles_queue_seek(&srt->q, s, stream_index,
+                                   min_ts, ts, max_ts, flags);
+}
+
+static int srt_read_close(AVFormatContext *s)
+{
+    SRTContext *srt = s->priv_data;
+    ff_subtitles_queue_clean(&srt->q);
+    return 0;
 }
 
 AVInputFormat ff_srt_demuxer = {
     .name        = "srt",
     .long_name   = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
+    .priv_data_size = sizeof(SRTContext),
     .read_probe  = srt_probe,
     .read_header = srt_read_header,
     .read_packet = srt_read_packet,
-    .flags       = AVFMT_GENERIC_INDEX,
+    .read_seek2  = srt_read_seek,
+    .read_close  = srt_read_close,
 };