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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-11-26 19:01:44 +02:00

avformat/smacker: add better seeking support

This commit is contained in:
Paul B Mahol 2022-04-06 22:25:05 +02:00
parent b2dd3e844d
commit 9d20f64f9c

View File

@ -94,6 +94,7 @@ static int smacker_read_header(AVFormatContext *s)
AVStream *st;
AVCodecParameters *par;
uint32_t magic, width, height, flags, treesize;
int64_t pos;
int i, ret, pts_inc;
int tbase;
@ -211,8 +212,13 @@ static int smacker_read_header(AVFormatContext *s)
smk->frm_flags = (void*)(smk->frm_size + smk->frames);
/* read frame info */
pos = 0;
for (i = 0; i < smk->frames; i++) {
smk->frm_size[i] = avio_rl32(pb);
if ((ret = av_add_index_entry(st, pos, i, smk->frm_size[i], 0,
(i == 0 || (smk->frm_size[i] & 1)) ? AVINDEX_KEYFRAME : 0)) < 0)
return ret;
pos += smk->frm_size[i];
}
if ((ret = ffio_read_size(pb, smk->frm_flags, smk->frames)) < 0 ||
/* load trees to extradata, they will be unpacked by decoder */
@ -335,7 +341,7 @@ static int smacker_read_packet(AVFormatContext *s, AVPacket *pkt)
if ((ret = av_new_packet(pkt, smk->frame_size + 769)) < 0)
goto next_frame;
flags = smk->new_palette;
if (smk->frm_size[smk->cur_frame] & 1)
if ((smk->frm_size[smk->cur_frame] & 1) || smk->cur_frame == 0)
flags |= 2;
pkt->data[0] = flags;
memcpy(pkt->data + 1, smk->pal, 768);
@ -344,6 +350,9 @@ static int smacker_read_packet(AVFormatContext *s, AVPacket *pkt)
goto next_frame;
pkt->stream_index = smk->videoindex;
pkt->pts = smk->cur_frame;
pkt->duration = 1;
if (flags & 2)
pkt->flags |= AV_PKT_FLAG_KEY;
smk->next_audio_index = 0;
smk->new_palette = 0;
smk->cur_frame++;
@ -359,20 +368,28 @@ next_frame:
static int smacker_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
AVStream *st = s->streams[stream_index];
SmackerContext *smk = s->priv_data;
int64_t ret;
int64_t pos;
int ret;
/* only rewinding to start is supported */
if (timestamp != 0) {
av_log(s, AV_LOG_ERROR,
"Random seeks are not supported (can only seek to start).\n");
if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
return -1;
if (timestamp < 0 || timestamp >= smk->frames)
return AVERROR(EINVAL);
}
if ((ret = avio_seek(s->pb, ffformatcontext(s)->data_offset, SEEK_SET)) < 0)
ret = av_index_search_timestamp(st, timestamp, flags);
if (ret < 0)
return ret;
smk->cur_frame = 0;
pos = ffformatcontext(s)->data_offset;
pos += ffstream(st)->index_entries[ret].pos;
pos = avio_seek(s->pb, pos, SEEK_SET);
if (pos < 0)
return pos;
smk->cur_frame = ret;
smk->next_audio_index = 0;
smk->new_palette = 0;
memset(smk->pal, 0, sizeof(smk->pal));