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-rw-r--r--libavformat/ffmdec.c723
1 files changed, 723 insertions, 0 deletions
diff --git a/libavformat/ffmdec.c b/libavformat/ffmdec.c
new file mode 100644
index 0000000000..987f419c96
--- /dev/null
+++ b/libavformat/ffmdec.c
@@ -0,0 +1,723 @@
+/*
+ * FFM (ffserver live feed) demuxer
+ * Copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of FFmpeg.
+ *
+ * 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.
+ *
+ * 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+
+#include "libavutil/intreadwrite.h"
+#include "libavutil/intfloat.h"
+#include "libavutil/opt.h"
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "avformat.h"
+#include "internal.h"
+#include "ffm.h"
+#include "avio_internal.h"
+
+static int ffm_is_avail_data(AVFormatContext *s, int size)
+{
+ FFMContext *ffm = s->priv_data;
+ int64_t pos, avail_size;
+ int len;
+
+ len = ffm->packet_end - ffm->packet_ptr;
+ if (size <= len)
+ return 1;
+ pos = avio_tell(s->pb);
+ if (!ffm->write_index) {
+ if (pos == ffm->file_size)
+ return AVERROR_EOF;
+ avail_size = ffm->file_size - pos;
+ } else {
+ if (pos == ffm->write_index) {
+ /* exactly at the end of stream */
+ return AVERROR(EAGAIN);
+ } else if (pos < ffm->write_index) {
+ avail_size = ffm->write_index - pos;
+ } else {
+ avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
+ }
+ }
+ avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
+ if (size <= avail_size)
+ return 1;
+ else
+ return AVERROR(EAGAIN);
+}
+
+static int ffm_resync(AVFormatContext *s, int state)
+{
+ av_log(s, AV_LOG_ERROR, "resyncing\n");
+ while (state != PACKET_ID) {
+ if (avio_feof(s->pb)) {
+ av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
+ return -1;
+ }
+ state = (state << 8) | avio_r8(s->pb);
+ }
+ return 0;
+}
+
+/* first is true if we read the frame header */
+static int ffm_read_data(AVFormatContext *s,
+ uint8_t *buf, int size, int header)
+{
+ FFMContext *ffm = s->priv_data;
+ AVIOContext *pb = s->pb;
+ int len, fill_size, size1, frame_offset, id;
+
+ size1 = size;
+ while (size > 0) {
+ redo:
+ len = ffm->packet_end - ffm->packet_ptr;
+ if (len < 0)
+ return -1;
+ if (len > size)
+ len = size;
+ if (len == 0) {
+ if (avio_tell(pb) == ffm->file_size)
+ avio_seek(pb, ffm->packet_size, SEEK_SET);
+ retry_read:
+ if (pb->buffer_size != ffm->packet_size) {
+ int64_t tell = avio_tell(pb);
+ ffio_set_buf_size(pb, ffm->packet_size);
+ avio_seek(pb, tell, SEEK_SET);
+ }
+ id = avio_rb16(pb); /* PACKET_ID */
+ if (id != PACKET_ID)
+ if (ffm_resync(s, id) < 0)
+ return -1;
+ fill_size = avio_rb16(pb);
+ ffm->dts = avio_rb64(pb);
+ frame_offset = avio_rb16(pb);
+ avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
+ ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
+ if (ffm->packet_end < ffm->packet || frame_offset < 0)
+ return -1;
+ /* if first packet or resynchronization packet, we must
+ handle it specifically */
+ if (ffm->first_packet || (frame_offset & 0x8000)) {
+ if (!frame_offset) {
+ /* This packet has no frame headers in it */
+ if (avio_tell(pb) >= ffm->packet_size * 3LL) {
+ avio_seek(pb, -ffm->packet_size * 2LL, SEEK_CUR);
+ goto retry_read;
+ }
+ /* This is bad, we cannot find a valid frame header */
+ return 0;
+ }
+ ffm->first_packet = 0;
+ if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
+ return -1;
+ ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
+ if (!header)
+ break;
+ } else {
+ ffm->packet_ptr = ffm->packet;
+ }
+ goto redo;
+ }
+ memcpy(buf, ffm->packet_ptr, len);
+ buf += len;
+ ffm->packet_ptr += len;
+ size -= len;
+ header = 0;
+ }
+ return size1 - size;
+}
+
+/* ensure that acutal seeking happens between FFM_PACKET_SIZE
+ and file_size - FFM_PACKET_SIZE */
+static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
+{
+ FFMContext *ffm = s->priv_data;
+ AVIOContext *pb = s->pb;
+ int64_t pos;
+
+ pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
+ pos = FFMAX(pos, FFM_PACKET_SIZE);
+ av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
+ return avio_seek(pb, pos, SEEK_SET);
+}
+
+static int64_t get_dts(AVFormatContext *s, int64_t pos)
+{
+ AVIOContext *pb = s->pb;
+ int64_t dts;
+
+ ffm_seek1(s, pos);
+ avio_skip(pb, 4);
+ dts = avio_rb64(pb);
+ av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
+ return dts;
+}
+
+static void adjust_write_index(AVFormatContext *s)
+{
+ FFMContext *ffm = s->priv_data;
+ AVIOContext *pb = s->pb;
+ int64_t pts;
+ //int64_t orig_write_index = ffm->write_index;
+ int64_t pos_min, pos_max;
+ int64_t pts_start;
+ int64_t ptr = avio_tell(pb);
+
+
+ pos_min = 0;
+ pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
+
+ pts_start = get_dts(s, pos_min);
+
+ pts = get_dts(s, pos_max);
+
+ if (pts - 100000 > pts_start)
+ goto end;
+
+ ffm->write_index = FFM_PACKET_SIZE;
+
+ pts_start = get_dts(s, pos_min);
+
+ pts = get_dts(s, pos_max);
+
+ if (pts - 100000 <= pts_start) {
+ while (1) {
+ int64_t newpos;
+ int64_t newpts;
+
+ newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
+
+ if (newpos == pos_min)
+ break;
+
+ newpts = get_dts(s, newpos);
+
+ if (newpts - 100000 <= pts) {
+ pos_max = newpos;
+ pts = newpts;
+ } else {
+ pos_min = newpos;
+ }
+ }
+ ffm->write_index += pos_max;
+ }
+
+ end:
+ avio_seek(pb, ptr, SEEK_SET);
+}
+
+
+static int ffm_close(AVFormatContext *s)
+{
+ int i;
+
+ for (i = 0; i < s->nb_streams; i++)
+ av_freep(&s->streams[i]->codec->rc_eq);
+
+ return 0;
+}
+
+static int ffm_append_recommended_configuration(AVStream *st, char **conf)
+{
+ int ret;
+ size_t newsize;
+ av_assert0(conf && st);
+ if (!*conf)
+ return 0;
+ if (!st->recommended_encoder_configuration) {
+ st->recommended_encoder_configuration = *conf;
+ *conf = 0;
+ return 0;
+ }
+ newsize = strlen(*conf) + strlen(st->recommended_encoder_configuration) + 2;
+ if ((ret = av_reallocp(&st->recommended_encoder_configuration, newsize)) < 0)
+ return ret;
+ av_strlcat(st->recommended_encoder_configuration, ",", newsize);
+ av_strlcat(st->recommended_encoder_configuration, *conf, newsize);
+ av_freep(conf);
+ return 0;
+}
+
+static int ffm2_read_header(AVFormatContext *s)
+{
+ FFMContext *ffm = s->priv_data;
+ AVStream *st;
+ AVIOContext *pb = s->pb;
+ AVCodecContext *codec;
+ int ret;
+ int f_main = 0, f_cprv, f_stvi, f_stau;
+ AVCodec *enc;
+ char *buffer;
+
+ ffm->packet_size = avio_rb32(pb);
+ if (ffm->packet_size != FFM_PACKET_SIZE) {
+ av_log(s, AV_LOG_ERROR, "Invalid packet size %d, expected size was %d\n",
+ ffm->packet_size, FFM_PACKET_SIZE);
+ ret = AVERROR_INVALIDDATA;
+ goto fail;
+ }
+
+ ffm->write_index = avio_rb64(pb);
+ /* get also filesize */
+ if (pb->seekable) {
+ ffm->file_size = avio_size(pb);
+ if (ffm->write_index && 0)
+ adjust_write_index(s);
+ } else {
+ ffm->file_size = (UINT64_C(1) << 63) - 1;
+ }
+
+ while(!avio_feof(pb)) {
+ unsigned id = avio_rb32(pb);
+ unsigned size = avio_rb32(pb);
+ int64_t next = avio_tell(pb) + size;
+ char rc_eq_buf[128];
+
+ if(!id)
+ break;
+
+ switch(id) {
+ case MKBETAG('M', 'A', 'I', 'N'):
+ if (f_main++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ avio_rb32(pb); /* nb_streams */
+ avio_rb32(pb); /* total bitrate */
+ break;
+ case MKBETAG('C', 'O', 'M', 'M'):
+ f_cprv = f_stvi = f_stau = 0;
+ st = avformat_new_stream(s, NULL);
+ if (!st) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ avpriv_set_pts_info(st, 64, 1, 1000000);
+
+ codec = st->codec;
+ /* generic info */
+ codec->codec_id = avio_rb32(pb);
+ codec->codec_type = avio_r8(pb);
+ codec->bit_rate = avio_rb32(pb);
+ codec->flags = avio_rb32(pb);
+ codec->flags2 = avio_rb32(pb);
+ codec->debug = avio_rb32(pb);
+ if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
+ if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
+ return AVERROR(ENOMEM);
+ }
+ break;
+ case MKBETAG('S', 'T', 'V', 'I'):
+ if (f_stvi++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ codec->time_base.num = avio_rb32(pb);
+ codec->time_base.den = avio_rb32(pb);
+ codec->width = avio_rb16(pb);
+ codec->height = avio_rb16(pb);
+ codec->gop_size = avio_rb16(pb);
+ codec->pix_fmt = avio_rb32(pb);
+ codec->qmin = avio_r8(pb);
+ codec->qmax = avio_r8(pb);
+ codec->max_qdiff = avio_r8(pb);
+ codec->qcompress = avio_rb16(pb) / 10000.0;
+ codec->qblur = avio_rb16(pb) / 10000.0;
+ codec->bit_rate_tolerance = avio_rb32(pb);
+ avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
+ codec->rc_eq = av_strdup(rc_eq_buf);
+ codec->rc_max_rate = avio_rb32(pb);
+ codec->rc_min_rate = avio_rb32(pb);
+ codec->rc_buffer_size = avio_rb32(pb);
+ codec->i_quant_factor = av_int2double(avio_rb64(pb));
+ codec->b_quant_factor = av_int2double(avio_rb64(pb));
+ codec->i_quant_offset = av_int2double(avio_rb64(pb));
+ codec->b_quant_offset = av_int2double(avio_rb64(pb));
+ codec->dct_algo = avio_rb32(pb);
+ codec->strict_std_compliance = avio_rb32(pb);
+ codec->max_b_frames = avio_rb32(pb);
+ codec->mpeg_quant = avio_rb32(pb);
+ codec->intra_dc_precision = avio_rb32(pb);
+ codec->me_method = avio_rb32(pb);
+ codec->mb_decision = avio_rb32(pb);
+ codec->nsse_weight = avio_rb32(pb);
+ codec->frame_skip_cmp = avio_rb32(pb);
+ codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
+ codec->codec_tag = avio_rb32(pb);
+ codec->thread_count = avio_r8(pb);
+ codec->coder_type = avio_rb32(pb);
+ codec->me_cmp = avio_rb32(pb);
+ codec->me_subpel_quality = avio_rb32(pb);
+ codec->me_range = avio_rb32(pb);
+ codec->keyint_min = avio_rb32(pb);
+ codec->scenechange_threshold = avio_rb32(pb);
+ codec->b_frame_strategy = avio_rb32(pb);
+ codec->qcompress = av_int2double(avio_rb64(pb));
+ codec->qblur = av_int2double(avio_rb64(pb));
+ codec->max_qdiff = avio_rb32(pb);
+ codec->refs = avio_rb32(pb);
+ break;
+ case MKBETAG('S', 'T', 'A', 'U'):
+ if (f_stau++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ codec->sample_rate = avio_rb32(pb);
+ codec->channels = avio_rl16(pb);
+ codec->frame_size = avio_rl16(pb);
+ break;
+ case MKBETAG('C', 'P', 'R', 'V'):
+ if (f_cprv++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ enc = avcodec_find_encoder(codec->codec_id);
+ if (enc && enc->priv_data_size && enc->priv_class) {
+ buffer = av_malloc(size + 1);
+ if (!buffer) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ avio_get_str(pb, size, buffer, size + 1);
+ if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
+ goto fail;
+ }
+ break;
+ case MKBETAG('S', '2', 'V', 'I'):
+ if (f_stvi++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ buffer = av_malloc(size);
+ if (!buffer) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ avio_get_str(pb, INT_MAX, buffer, size);
+ av_set_options_string(codec, buffer, "=", ",");
+ if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)
+ goto fail;
+ break;
+ case MKBETAG('S', '2', 'A', 'U'):
+ if (f_stau++) {
+ ret = AVERROR(EINVAL);
+ goto fail;
+ }
+ buffer = av_malloc(size);
+ if (!buffer) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+ avio_get_str(pb, INT_MAX, buffer, size);
+ av_set_options_string(codec, buffer, "=", ",");
+ ffm_append_recommended_configuration(st, &buffer);
+ break;
+ }
+ avio_seek(pb, next, SEEK_SET);
+ }
+
+ /* get until end of block reached */
+ while ((avio_tell(pb) % ffm->packet_size) != 0)
+ avio_r8(pb);
+
+ /* init packet demux */
+ ffm->packet_ptr = ffm->packet;
+ ffm->packet_end = ffm->packet;
+ ffm->frame_offset = 0;
+ ffm->dts = 0;
+ ffm->read_state = READ_HEADER;
+ ffm->first_packet = 1;
+ return 0;
+ fail:
+ ffm_close(s);
+ return ret;
+}
+
+static int ffm_read_header(AVFormatContext *s)
+{
+ FFMContext *ffm = s->priv_data;
+ AVStream *st;
+ AVIOContext *pb = s->pb;
+ AVCodecContext *codec;
+ int i, nb_streams;
+ uint32_t tag;
+
+ /* header */
+ tag = avio_rl32(pb);
+ if (tag == MKTAG('F', 'F', 'M', '2'))
+ return ffm2_read_header(s);
+ if (tag != MKTAG('F', 'F', 'M', '1'))
+ goto fail;
+ ffm->packet_size = avio_rb32(pb);
+ if (ffm->packet_size != FFM_PACKET_SIZE)
+ goto fail;
+ ffm->write_index = avio_rb64(pb);
+ /* get also filesize */
+ if (pb->seekable) {
+ ffm->file_size = avio_size(pb);
+ if (ffm->write_index && 0)
+ adjust_write_index(s);
+ } else {
+ ffm->file_size = (UINT64_C(1) << 63) - 1;
+ }
+
+ nb_streams = avio_rb32(pb);
+ avio_rb32(pb); /* total bitrate */
+ /* read each stream */
+ for(i=0;i<nb_streams;i++) {
+ char rc_eq_buf[128];
+
+ st = avformat_new_stream(s, NULL);
+ if (!st)
+ goto fail;
+
+ avpriv_set_pts_info(st, 64, 1, 1000000);
+
+ codec = st->codec;
+ /* generic info */
+ codec->codec_id = avio_rb32(pb);
+ codec->codec_type = avio_r8(pb); /* codec_type */
+ codec->bit_rate = avio_rb32(pb);
+ codec->flags = avio_rb32(pb);
+ codec->flags2 = avio_rb32(pb);
+ codec->debug = avio_rb32(pb);
+ /* specific info */
+ switch(codec->codec_type) {
+ case AVMEDIA_TYPE_VIDEO:
+ codec->time_base.num = avio_rb32(pb);
+ codec->time_base.den = avio_rb32(pb);
+ codec->width = avio_rb16(pb);
+ codec->height = avio_rb16(pb);
+ codec->gop_size = avio_rb16(pb);
+ codec->pix_fmt = avio_rb32(pb);
+ codec->qmin = avio_r8(pb);
+ codec->qmax = avio_r8(pb);
+ codec->max_qdiff = avio_r8(pb);
+ codec->qcompress = avio_rb16(pb) / 10000.0;
+ codec->qblur = avio_rb16(pb) / 10000.0;
+ codec->bit_rate_tolerance = avio_rb32(pb);
+ avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
+ codec->rc_eq = av_strdup(rc_eq_buf);
+ codec->rc_max_rate = avio_rb32(pb);
+ codec->rc_min_rate = avio_rb32(pb);
+ codec->rc_buffer_size = avio_rb32(pb);
+ codec->i_quant_factor = av_int2double(avio_rb64(pb));
+ codec->b_quant_factor = av_int2double(avio_rb64(pb));
+ codec->i_quant_offset = av_int2double(avio_rb64(pb));
+ codec->b_quant_offset = av_int2double(avio_rb64(pb));
+ codec->dct_algo = avio_rb32(pb);
+ codec->strict_std_compliance = avio_rb32(pb);
+ codec->max_b_frames = avio_rb32(pb);
+ codec->mpeg_quant = avio_rb32(pb);
+ codec->intra_dc_precision = avio_rb32(pb);
+ codec->me_method = avio_rb32(pb);
+ codec->mb_decision = avio_rb32(pb);
+ codec->nsse_weight = avio_rb32(pb);
+ codec->frame_skip_cmp = avio_rb32(pb);
+ codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
+ codec->codec_tag = avio_rb32(pb);
+ codec->thread_count = avio_r8(pb);
+ codec->coder_type = avio_rb32(pb);
+ codec->me_cmp = avio_rb32(pb);
+ codec->me_subpel_quality = avio_rb32(pb);
+ codec->me_range = avio_rb32(pb);
+ codec->keyint_min = avio_rb32(pb);
+ codec->scenechange_threshold = avio_rb32(pb);
+ codec->b_frame_strategy = avio_rb32(pb);
+ codec->qcompress = av_int2double(avio_rb64(pb));
+ codec->qblur = av_int2double(avio_rb64(pb));
+ codec->max_qdiff = avio_rb32(pb);
+ codec->refs = avio_rb32(pb);
+ break;
+ case AVMEDIA_TYPE_AUDIO:
+ codec->sample_rate = avio_rb32(pb);
+ codec->channels = avio_rl16(pb);
+ codec->frame_size = avio_rl16(pb);
+ break;
+ default:
+ goto fail;
+ }
+ if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
+ if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)
+ return AVERROR(ENOMEM);
+ }
+ }
+
+ /* get until end of block reached */
+ while ((avio_tell(pb) % ffm->packet_size) != 0)
+ avio_r8(pb);
+
+ /* init packet demux */
+ ffm->packet_ptr = ffm->packet;
+ ffm->packet_end = ffm->packet;
+ ffm->frame_offset = 0;
+ ffm->dts = 0;
+ ffm->read_state = READ_HEADER;
+ ffm->first_packet = 1;
+ return 0;
+ fail:
+ ffm_close(s);
+ return -1;
+}
+
+/* return < 0 if eof */
+static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+ int size;
+ FFMContext *ffm = s->priv_data;
+ int duration, ret;
+
+ switch(ffm->read_state) {
+ case READ_HEADER:
+ if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
+ return ret;
+
+ av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
+ avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
+ if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
+ FRAME_HEADER_SIZE)
+ return -1;
+ if (ffm->header[1] & FLAG_DTS)
+ if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
+ return -1;
+ ffm->read_state = READ_DATA;
+ /* fall through */
+ case READ_DATA:
+ size = AV_RB24(ffm->header + 2);
+ if ((ret = ffm_is_avail_data(s, size)) < 0)
+ return ret;
+
+ duration = AV_RB24(ffm->header + 5);
+
+ if (av_new_packet(pkt, size) < 0) {
+ return AVERROR(ENOMEM);
+ }
+ pkt->stream_index = ffm->header[0];
+ if ((unsigned)pkt->stream_index >= s->nb_streams) {
+ av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
+ av_free_packet(pkt);
+ ffm->read_state = READ_HEADER;
+ return -1;
+ }
+ pkt->pos = avio_tell(s->pb);
+ if (ffm->header[1] & FLAG_KEY_FRAME)
+ pkt->flags |= AV_PKT_FLAG_KEY;
+
+ ffm->read_state = READ_HEADER;
+ if (ffm_read_data(s, pkt->data, size, 0) != size) {
+ /* bad case: desynchronized packet. we cancel all the packet loading */
+ av_free_packet(pkt);
+ return -1;
+ }
+ pkt->pts = AV_RB64(ffm->header+8);
+ if (ffm->header[1] & FLAG_DTS)
+ pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
+ else
+ pkt->dts = pkt->pts;
+ pkt->duration = duration;
+ break;
+ }
+ return 0;
+}
+
+/* seek to a given time in the file. The file read pointer is
+ positioned at or before pts. XXX: the following code is quite
+ approximative */
+static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
+{
+ FFMContext *ffm = s->priv_data;
+ int64_t pos_min, pos_max, pos;
+ int64_t pts_min, pts_max, pts;
+ double pos1;
+
+ av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
+ /* find the position using linear interpolation (better than
+ dichotomy in typical cases) */
+ if (ffm->write_index && ffm->write_index < ffm->file_size) {
+ if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
+ pos_min = FFM_PACKET_SIZE;
+ pos_max = ffm->write_index - FFM_PACKET_SIZE;
+ } else {
+ pos_min = ffm->write_index;
+ pos_max = ffm->file_size - FFM_PACKET_SIZE;
+ }
+ } else {
+ pos_min = FFM_PACKET_SIZE;
+ pos_max = ffm->file_size - FFM_PACKET_SIZE;
+ }
+ while (pos_min <= pos_max) {
+ pts_min = get_dts(s, pos_min);
+ pts_max = get_dts(s, pos_max);
+ if (pts_min > wanted_pts || pts_max <= wanted_pts) {
+ pos = pts_min > wanted_pts ? pos_min : pos_max;
+ goto found;
+ }
+ /* linear interpolation */
+ pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
+ (double)(pts_max - pts_min);
+ pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
+ if (pos <= pos_min)
+ pos = pos_min;
+ else if (pos >= pos_max)
+ pos = pos_max;
+ pts = get_dts(s, pos);
+ /* check if we are lucky */
+ if (pts == wanted_pts) {
+ goto found;
+ } else if (pts > wanted_pts) {
+ pos_max = pos - FFM_PACKET_SIZE;
+ } else {
+ pos_min = pos + FFM_PACKET_SIZE;
+ }
+ }
+ pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
+
+ found:
+ if (ffm_seek1(s, pos) < 0)
+ return -1;
+
+ /* reset read state */
+ ffm->read_state = READ_HEADER;
+ ffm->packet_ptr = ffm->packet;
+ ffm->packet_end = ffm->packet;
+ ffm->first_packet = 1;
+
+ return 0;
+}
+
+static int ffm_probe(AVProbeData *p)
+{
+ if (
+ p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
+ (p->buf[3] == '1' || p->buf[3] == '2'))
+ return AVPROBE_SCORE_MAX + 1;
+ return 0;
+}
+
+AVInputFormat ff_ffm_demuxer = {
+ .name = "ffm",
+ .long_name = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
+ .priv_data_size = sizeof(FFMContext),
+ .read_probe = ffm_probe,
+ .read_header = ffm_read_header,
+ .read_packet = ffm_read_packet,
+ .read_close = ffm_close,
+ .read_seek = ffm_seek,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-09 09:13:33 +0000