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/*
* Copyright (c) 2013 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "./webmdec.h"
#include <stdarg.h>
#include "third_party/nestegg/include/nestegg/nestegg.h"
static int nestegg_read_cb(void *buffer, size_t length, void *userdata) {
FILE *f = userdata;
if (fread(buffer, 1, length, f) < length) {
if (ferror(f))
return -1;
if (feof(f))
return 0;
}
return 1;
}
static int nestegg_seek_cb(int64_t offset, int whence, void *userdata) {
switch (whence) {
case NESTEGG_SEEK_SET:
whence = SEEK_SET;
break;
case NESTEGG_SEEK_CUR:
whence = SEEK_CUR;
break;
case NESTEGG_SEEK_END:
whence = SEEK_END;
break;
};
return fseek(userdata, (int32_t)offset, whence) ? -1 : 0;
}
static int64_t nestegg_tell_cb(void *userdata) {
return ftell(userdata);
}
static void nestegg_log_cb(nestegg *context,
unsigned int severity,
char const *format, ...) {
va_list ap;
va_start(ap, format);
vfprintf(stderr, format, ap);
fprintf(stderr, "\n");
va_end(ap);
}
int file_is_webm(struct WebmInputContext *webm_ctx,
struct VpxInputContext *vpx_ctx) {
uint32_t i, n;
int track_type = -1;
int codec_id;
nestegg_io io = {nestegg_read_cb, nestegg_seek_cb, nestegg_tell_cb, 0};
nestegg_video_params params;
io.userdata = vpx_ctx->file;
if (nestegg_init(&webm_ctx->nestegg_ctx, io, NULL, -1))
goto fail;
if (nestegg_track_count(webm_ctx->nestegg_ctx, &n))
goto fail;
for (i = 0; i < n; i++) {
track_type = nestegg_track_type(webm_ctx->nestegg_ctx, i);
if (track_type == NESTEGG_TRACK_VIDEO)
break;
else if (track_type < 0)
goto fail;
}
codec_id = nestegg_track_codec_id(webm_ctx->nestegg_ctx, i);
if (codec_id == NESTEGG_CODEC_VP8) {
vpx_ctx->fourcc = VP8_FOURCC;
} else if (codec_id == NESTEGG_CODEC_VP9) {
vpx_ctx->fourcc = VP9_FOURCC;
} else {
fatal("Not VPx video, quitting.\n");
}
webm_ctx->video_track = i;
if (nestegg_track_video_params(webm_ctx->nestegg_ctx, i, ¶ms))
goto fail;
vpx_ctx->framerate.denominator = 0;
vpx_ctx->framerate.numerator = 0;
vpx_ctx->width = params.width;
vpx_ctx->height = params.height;
return 1;
fail:
webm_ctx->nestegg_ctx = NULL;
rewind(vpx_ctx->file);
return 0;
}
int webm_read_frame(struct WebmInputContext *webm_ctx,
uint8_t **buffer,
size_t *bytes_in_buffer,
size_t *buffer_size) {
if (webm_ctx->chunk >= webm_ctx->chunks) {
uint32_t track;
do {
/* End of this packet, get another. */
if (webm_ctx->pkt) {
nestegg_free_packet(webm_ctx->pkt);
webm_ctx->pkt = NULL;
}
if (nestegg_read_packet(webm_ctx->nestegg_ctx, &webm_ctx->pkt) <= 0 ||
nestegg_packet_track(webm_ctx->pkt, &track)) {
return 1;
}
} while (track != webm_ctx->video_track);
if (nestegg_packet_count(webm_ctx->pkt, &webm_ctx->chunks))
return 1;
webm_ctx->chunk = 0;
}
if (nestegg_packet_data(webm_ctx->pkt, webm_ctx->chunk,
buffer, bytes_in_buffer)) {
return 1;
}
webm_ctx->chunk++;
return 0;
}
int webm_guess_framerate(struct WebmInputContext *webm_ctx,
struct VpxInputContext *vpx_ctx) {
uint32_t i;
uint64_t tstamp = 0;
/* Check to see if we can seek before we parse any data. */
if (nestegg_track_seek(webm_ctx->nestegg_ctx, webm_ctx->video_track, 0)) {
warn("Failed to guess framerate (no Cues), set to 30fps.\n");
vpx_ctx->framerate.numerator = 30;
vpx_ctx->framerate.denominator = 1;
return 0;
}
/* Guess the framerate. Read up to 1 second, or 50 video packets,
* whichever comes first.
*/
for (i = 0; tstamp < 1000000000 && i < 50;) {
nestegg_packet *pkt;
uint32_t track;
if (nestegg_read_packet(webm_ctx->nestegg_ctx, &pkt) <= 0)
break;
nestegg_packet_track(pkt, &track);
if (track == webm_ctx->video_track) {
nestegg_packet_tstamp(pkt, &tstamp);
++i;
}
nestegg_free_packet(pkt);
}
if (nestegg_track_seek(webm_ctx->nestegg_ctx, webm_ctx->video_track, 0))
goto fail;
vpx_ctx->framerate.numerator = (i - 1) * 1000000;
vpx_ctx->framerate.denominator = (int)(tstamp / 1000);
return 0;
fail:
nestegg_destroy(webm_ctx->nestegg_ctx);
webm_ctx->nestegg_ctx = NULL;
rewind(vpx_ctx->file);
return 1;
}
void webm_free(struct WebmInputContext *webm_ctx) {
if (webm_ctx && webm_ctx->nestegg_ctx) {
if (webm_ctx->pkt)
nestegg_free_packet(webm_ctx->pkt);
nestegg_destroy(webm_ctx->nestegg_ctx);
}
}
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