[FFmpeg-devel] [PATCH 3/5] avformat/imf: Demuxer implementation
Paul B Mahol
onemda at gmail.com
Wed Oct 27 10:54:08 EEST 2021
On Fri, Oct 8, 2021 at 1:42 AM <pal at sandflow.com> wrote:
> From: Pierre-Anthony Lemieux <pal at sandflow.com>
>
> Signed-off-by: Pierre-Anthony Lemieux <pal at sandflow.com>
> ---
>
> Notes:
> Implements the IMF demuxer.
>
> libavformat/imfdec.c | 660 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 660 insertions(+)
> create mode 100644 libavformat/imfdec.c
>
> diff --git a/libavformat/imfdec.c b/libavformat/imfdec.c
> new file mode 100644
> index 0000000000..0c64fe0c03
> --- /dev/null
> +++ b/libavformat/imfdec.c
> @@ -0,0 +1,660 @@
> +/*
> + * Copyright (c) Sandflow Consulting LLC
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions are
> met:
> + *
> + * * Redistributions of source code must retain the above copyright
> notice, this
> + * list of conditions and the following disclaimer.
> + * * Redistributions in binary form must reproduce the above copyright
> notice,
> + * this list of conditions and the following disclaimer in the
> documentation
> + * and/or other materials provided with the distribution.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> "AS IS"
> + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
> THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> PURPOSE
> + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
> BE
> + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
> + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
> BUSINESS
> + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
> + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
> THE
> + * POSSIBILITY OF SUCH DAMAGE.
> + *
> + * 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
> + */
> +
> +/**
> + * Demuxes an IMF Composition
> + *
> + * References
> + * OV 2067-0:2018 - SMPTE Overview Document - Interoperable Master Format
> + * ST 2067-2:2020 - SMPTE Standard - Interoperable Master Format — Core
> Constraints
> + * ST 2067-3:2020 - SMPTE Standard - Interoperable Master Format —
> Composition Playlist
> + * ST 2067-5:2020 - SMPTE Standard - Interoperable Master Format —
> Essence Component
> + * ST 2067-20:2016 - SMPTE Standard - Interoperable Master Format —
> Application #2
> + * ST 2067-21:2020 - SMPTE Standard - Interoperable Master Format —
> Application #2 Extended
> + * ST 2067-102:2017 - SMPTE Standard - Interoperable Master Format —
> Common Image Pixel Color Schemes
> + * ST 429-9:2007 - SMPTE Standard - D-Cinema Packaging — Asset Mapping
> and File Segmentation
> + *
> + * @author Marc-Antoine Arnaud
> + * @author Valentin Noel
> + * @file
> + * @ingroup lavu_imf
> + */
> +
> +#include "imf.h"
> +#include "imf_internal.h"
> +#include "internal.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/bprint.h"
> +#include "libavutil/avstring.h"
> +#include "mxf.h"
> +#include "url.h"
> +#include <libxml/parser.h>
> +#include <inttypes.h>
> +
> +#define MAX_BPRINT_READ_SIZE (UINT_MAX - 1)
> +#define DEFAULT_ASSETMAP_SIZE 8 * 1024
> +
> +typedef struct IMFVirtualTrackResourcePlaybackCtx {
> + IMFAssetLocator *locator;
> + IMFTrackFileResource *resource;
> + AVFormatContext *ctx;
> +} IMFVirtualTrackResourcePlaybackCtx;
> +
> +typedef struct IMFVirtualTrackPlaybackCtx {
> + // Track index in playlist
> + int32_t index;
> + // Time counters
> + AVRational current_timestamp;
> + AVRational duration;
> + // Resources
> + unsigned int resource_count;
> + IMFVirtualTrackResourcePlaybackCtx **resources;
> + // Decoding cursors
> + uint32_t current_resource_index;
> + int64_t last_pts;
> +} IMFVirtualTrackPlaybackCtx;
> +
> +typedef struct IMFContext {
> + const AVClass *class;
> + const char *base_url;
> + char *asset_map_paths;
> + AVIOInterruptCB *interrupt_callback;
> + AVDictionary *avio_opts;
> + IMFCPL *cpl;
> + IMFAssetLocatorMap *asset_locator_map;
> + unsigned int track_count;
> + IMFVirtualTrackPlaybackCtx **tracks;
> +} IMFContext;
> +
> +int is_url(const char *string) {
> + char *substr = strstr(string, "://");
> + return substr != NULL;
> +}
> +
> +int is_unix_absolute_path(const char *string) {
> + char *substr = strstr(string, "/");
> + int index = (int)(substr - string);
> + return index == 0;
> +}
> +
> +int is_dos_absolute_path(const char *string) {
>
Are those function static or not? Also bad code style above and bellow that
does not match ffmpeg code style at all.
+ // Absolute path case: `C:\path\to\somwhere`
> + char *substr = strstr(string, ":\\");
> + int index = (int)(substr - string);
> + if (index == 1) {
> + return 1;
> + }
> +
> + // Absolute path case: `C:/path/to/somwhere`
> + substr = strstr(string, ":/");
> + index = (int)(substr - string);
> + if (index == 1) {
> + return 1;
> + }
> +
> + // Network path case: `\\path\to\somwhere`
> + substr = strstr(string, "\\\\");
> + index = (int)(substr - string);
> + return index == 0;
> +}
> +
> +int parse_imf_asset_map_from_xml_dom(AVFormatContext *s, xmlDocPtr doc,
> IMFAssetLocatorMap **asset_map, const char *base_url) {
> + xmlNodePtr asset_map_element = NULL;
> + xmlNodePtr node = NULL;
> + char *uri;
> + int ret = 0;
> +
> + IMFAssetLocator *asset = NULL;
> +
> + asset_map_element = xmlDocGetRootElement(doc);
> +
> + if (!asset_map_element) {
> + av_log(s, AV_LOG_ERROR, "Unable to parse asset map XML - missing
> root node\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + if (asset_map_element->type != XML_ELEMENT_NODE ||
> av_strcasecmp(asset_map_element->name, "AssetMap")) {
> + av_log(s, AV_LOG_ERROR, "Unable to parse asset map XML - wrong
> root node name[%s] type[%d]\n", asset_map_element->name,
> (int)asset_map_element->type);
> + return AVERROR_INVALIDDATA;
> + }
> +
> + // parse asset locators
> +
> + if (!(node = xml_get_child_element_by_name(asset_map_element,
> "AssetList"))) {
> + av_log(s, AV_LOG_ERROR, "Unable to parse asset map XML - missing
> AssetList node\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + node = xmlFirstElementChild(node);
> + while (node) {
> + if (av_strcasecmp(node->name, "Asset") != 0) {
> + continue;
> + }
> +
> + asset = av_malloc(sizeof(IMFAssetLocator));
> +
> + if (xml_read_UUID(xml_get_child_element_by_name(node, "Id"),
> asset->uuid)) {
> + av_log(s, AV_LOG_ERROR, "Could not parse UUID from asset in
> asset map.\n");
> + av_freep(&asset);
> + return 1;
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "Found asset id: " UUID_FORMAT "\n",
> UID_ARG(asset->uuid));
> +
> + if (!(node = xml_get_child_element_by_name(node, "ChunkList"))) {
+ av_log(s, AV_LOG_ERROR, "Unable to parse asset map XML -
> missing ChunkList node\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + if (!(node = xml_get_child_element_by_name(node, "Chunk"))) {
> + av_log(s, AV_LOG_ERROR, "Unable to parse asset map XML -
> missing Chunk node\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + uri = xmlNodeGetContent(xml_get_child_element_by_name(node,
> "Path"));
> +
> + if (!is_url(uri) && !is_unix_absolute_path(uri) &&
> !is_dos_absolute_path(uri)) {
> + uri = av_append_path_component(base_url, uri);
> + }
> +
> + asset->absolute_uri = strdup(uri);
>
av_strdup()
also does not check for failure.
> + av_free(uri);
> +
> + av_log(s, AV_LOG_DEBUG, "Found asset absolute URI: %s\n",
> asset->absolute_uri);
> +
> + node = xmlNextElementSibling(node->parent->parent);
> +
> + (*asset_map)->assets = av_realloc((*asset_map)->assets,
> ((*asset_map)->asset_count + 1) * sizeof(IMFAssetLocator));
>
Leaks on allocation error. Invalid write on allocation error. Not only for
this line but all lines that use this function.
> + (*asset_map)->assets[(*asset_map)->asset_count++] = asset;
> + }
> +
> + return ret;
> +}
> +
> +IMFAssetLocatorMap *imf_asset_locator_map_alloc(void) {
> + IMFAssetLocatorMap *asset_map;
> +
> + asset_map = av_malloc(sizeof(IMFAssetLocatorMap));
> + if (!asset_map)
> + return NULL;
> +
> + asset_map->assets = NULL;
> + asset_map->asset_count = 0;
> + return asset_map;
> +}
> +
> +void imf_asset_locator_map_free(IMFAssetLocatorMap *asset_map) {
> + if (asset_map == NULL) {
> + return;
> + }
> +
+ for (int i = 0; i < asset_map->asset_count; ++i) {
> + av_free(asset_map->assets[i]);
>
Invalid free and invalid read access if allocation was unsuccessful.
Please check for error cases all over patches, not just this single case.
+ }
> +
> + av_freep(&asset_map->assets);
> + av_freep(&asset_map);
> +}
> +
> +static int parse_assetmap(AVFormatContext *s, const char *url,
> AVIOContext *in) {
> + IMFContext *c = s->priv_data;
> + struct AVBPrint buf;
> + AVDictionary *opts = NULL;
> + xmlDoc *doc = NULL;
> + const char *base_url;
> +
> + int close_in = 0;
> + int ret;
> + int64_t filesize;
> +
> + base_url = av_dirname(strdup(url));
> + if (c->asset_locator_map == NULL) {
> + c->asset_locator_map = imf_asset_locator_map_alloc();
> + if (!c->asset_locator_map) {
> + av_log(s, AV_LOG_ERROR, "Unable to allocate asset map
> locator\n");
> + return AVERROR_BUG;
> + }
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "Asset Map URL: %s\n", url);
> +
> + if (!in) {
> + close_in = 1;
> +
> + av_dict_copy(&opts, c->avio_opts, 0);
> + ret = avio_open2(&in, url, AVIO_FLAG_READ, c->interrupt_callback,
> &opts);
> + av_dict_free(&opts);
> + if (ret < 0)
> + return ret;
> + }
> +
> + filesize = avio_size(in);
> + filesize = filesize > 0 ? filesize : DEFAULT_ASSETMAP_SIZE;
> +
> + av_bprint_init(&buf, filesize + 1, AV_BPRINT_SIZE_UNLIMITED);
> +
> + if ((ret = avio_read_to_bprint(in, &buf, MAX_BPRINT_READ_SIZE)) < 0
> || !avio_feof(in) || (filesize = buf.len) == 0) {
> + av_log(s, AV_LOG_ERROR, "Unable to read to asset map '%s'\n",
> url);
> + if (ret == 0)
> + ret = AVERROR_INVALIDDATA;
> + } else {
> + LIBXML_TEST_VERSION
> +
> + doc = xmlReadMemory(buf.str, filesize, url, NULL, 0);
> +
> + ret = parse_imf_asset_map_from_xml_dom(s, doc,
> &c->asset_locator_map, base_url);
> + if (ret != 0) {
> + goto cleanup;
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "Found %d assets from %s\n",
> c->asset_locator_map->asset_count, url);
> +
> + cleanup:
> + xmlFreeDoc(doc);
> + }
> + if (close_in) {
> + avio_close(in);
> + }
> + return ret;
> +}
> +
> +static IMFAssetLocator *find_asset_map_locator(IMFAssetLocatorMap
> *asset_map, UUID uuid) {
> + IMFAssetLocator *asset_locator;
> + for (int i = 0; i < asset_map->asset_count; ++i) {
> + asset_locator = asset_map->assets[i];
> + if (memcmp(asset_map->assets[i]->uuid, uuid, 16) == 0) {
> + return asset_locator;
> + }
> + }
> + return NULL;
> +}
> +
> +static int open_track_resource_context(AVFormatContext *s,
> IMFVirtualTrackResourcePlaybackCtx *track_resource) {
> + int ret = 0;
> + int64_t entry_point;
> +
> + if (!track_resource->ctx) {
> + track_resource->ctx = avformat_alloc_context();
> + }
> +
> + if (track_resource->ctx->iformat) {
> + av_log(s, AV_LOG_DEBUG, "Input context already opened for %s.\n",
> track_resource->locator->absolute_uri);
> + return ret;
> + }
> +
> + ret = avformat_open_input(&track_resource->ctx,
> track_resource->locator->absolute_uri, NULL, NULL);
> + if (ret < 0) {
> + av_log(s, AV_LOG_ERROR, "Could not open %s input context: %s\n",
> track_resource->locator->absolute_uri, av_err2str(ret));
> + goto cleanup;
> + }
> +
> + ret = avformat_find_stream_info(track_resource->ctx, NULL);
> + if (ret < 0) {
> + av_log(s, AV_LOG_ERROR, "Could not find %s stream information:
> %s\n", track_resource->locator->absolute_uri, av_err2str(ret));
> + goto cleanup;
> + }
> +
> + // Compare the source timebase to the resource edit rate, considering
> the first stream of the source file
> + if (av_cmp_q(track_resource->ctx->streams[0]->time_base,
> av_inv_q(track_resource->resource->base.edit_rate))) {
> + av_log(s, AV_LOG_WARNING, "Incoherent source stream timebase
> %d/%d regarding resource edit rate: %d/%d",
> track_resource->ctx->streams[0]->time_base.num,
> track_resource->ctx->streams[0]->time_base.den,
> track_resource->resource->base.edit_rate.den,
> track_resource->resource->base.edit_rate.num);
> + }
> +
> + entry_point = (int64_t)track_resource->resource->base.entry_point *
> track_resource->resource->base.edit_rate.den * AV_TIME_BASE /
> track_resource->resource->base.edit_rate.num;
> +
> + if (entry_point) {
> + av_log(s, AV_LOG_DEBUG, "Seek at resource %s entry point: %ld\n",
> track_resource->locator->absolute_uri,
> track_resource->resource->base.entry_point);
> + ret = avformat_seek_file(track_resource->ctx, -1, entry_point,
> entry_point, entry_point, 0);
> + if (ret < 0) {
> + av_log(s, AV_LOG_ERROR, "Could not seek at %" PRId64 "on %s:
> %s\n", entry_point, track_resource->locator->absolute_uri, av_err2str(ret));
> + goto cleanup;
> + }
> + }
> +
> + return ret;
> +cleanup:
> + avformat_free_context(track_resource->ctx);
> + return ret;
> +}
> +
> +static int open_track_file_resource(AVFormatContext *s,
> IMFTrackFileResource *track_file_resource, IMFVirtualTrackPlaybackCtx
> *track) {
> + IMFContext *c = s->priv_data;
> + IMFVirtualTrackResourcePlaybackCtx *track_resource;
> + IMFAssetLocator *asset_locator;
> +
> + int ret;
> +
> + if (!(asset_locator = find_asset_map_locator(c->asset_locator_map,
> track_file_resource->track_file_uuid))) {
> + av_log(s, AV_LOG_ERROR, "Could not find asset locator for UUID: "
> UUID_FORMAT "\n", UID_ARG(track_file_resource->track_file_uuid));
> + return AVERROR_INVALIDDATA;
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "Found locator for " UUID_FORMAT ": %s\n",
> UID_ARG(asset_locator->uuid), asset_locator->absolute_uri);
> +
> + track_resource =
> av_mallocz(sizeof(IMFVirtualTrackResourcePlaybackCtx));
> + track_resource->locator = asset_locator;
> + track_resource->resource = track_file_resource;
> +
> + if ((ret = open_track_resource_context(s, track_resource)) != 0) {
> + return ret;
> + }
> +
> + for (int repetition = 0; repetition <
> track_file_resource->base.repeat_count; ++repetition) {
> + track->resources = av_realloc(track->resources,
> (track->resource_count + 1) * sizeof(IMFVirtualTrackResourcePlaybackCtx));
> + track->resources[track->resource_count++] = track_resource;
> + track->duration = av_add_q(track->duration,
> av_make_q((int)track_resource->resource->base.duration *
> track_resource->resource->base.edit_rate.den,
> track_resource->resource->base.edit_rate.num));
> + }
> +
> + return ret;
> +}
> +
> +static int open_virtual_track(AVFormatContext *s,
> IMFTrackFileVirtualTrack *virtual_track, int32_t track_index) {
> + IMFContext *c = s->priv_data;
> + IMFVirtualTrackPlaybackCtx *track;
> + int ret = 0;
> +
> + track = av_mallocz(sizeof(IMFVirtualTrackPlaybackCtx));
> + track->index = track_index;
> + track->duration = av_make_q(0, INT32_MAX);
> +
> + for (int i = 0; i < virtual_track->resource_count; i++) {
> + av_log(s, AV_LOG_DEBUG, "Open stream from file " UUID_FORMAT ",
> stream %d\n", UID_ARG(virtual_track->resources[i].track_file_uuid), i);
> + if ((ret = open_track_file_resource(s,
> &virtual_track->resources[i], track)) != 0) {
> + av_log(s, AV_LOG_ERROR, "Could not open image track resource
> " UUID_FORMAT "\n", UID_ARG(virtual_track->resources[i].track_file_uuid));
> + return ret;
> + }
> + }
> +
> + track->current_timestamp = av_make_q(0, track->duration.den);
> +
> + c->tracks = av_realloc(c->tracks, (c->track_count + 1) *
> sizeof(IMFVirtualTrackPlaybackCtx));
> + c->tracks[c->track_count++] = track;
> +
> + return ret;
> +}
> +
> +static void
> imf_virtual_track_playback_context_free(IMFVirtualTrackPlaybackCtx *track) {
> + if (!track) {
> + return;
> + }
> +
> + for (int i = 0; i < track->resource_count; ++i) {
> + if (!track->resources[i]) {
> + continue;
> + }
> +
> + if (track->resources[i]->ctx &&
> track->resources[i]->ctx->iformat) {
> + avformat_free_context(track->resources[i]->ctx);
> + track->resources[i]->ctx = NULL;
> + }
> + }
> +}
> +
> +static int set_context_streams_from_tracks(AVFormatContext *s) {
> + IMFContext *c = s->priv_data;
> +
> + AVStream *asset_stream;
> + AVStream *first_resource_stream;
> +
> + int ret = 0;
> +
> + for (int i = 0; i < c->track_count; ++i) {
> + // Open the first resource of the track to get stream information
> + first_resource_stream =
> c->tracks[i]->resources[0]->ctx->streams[0];
> +
> + av_log(s, AV_LOG_DEBUG, "Open the first resource of track %d\n",
> c->tracks[i]->index);
> +
> + // Copy stream information
> + asset_stream = avformat_new_stream(s, NULL);
> + asset_stream->id = i;
> + if ((ret = avcodec_parameters_copy(asset_stream->codecpar,
> first_resource_stream->codecpar)) < 0) {
> + av_log(s, AV_LOG_ERROR, "Could not copy stream parameters\n");
> + break;
> + }
> + avpriv_set_pts_info(asset_stream,
> first_resource_stream->pts_wrap_bits, first_resource_stream->time_base.num,
> first_resource_stream->time_base.den);
> + asset_stream->duration =
> (int64_t)av_q2d(av_mul_q(c->tracks[i]->duration,
> av_inv_q(asset_stream->time_base)));
> + }
> +
> + return ret;
> +}
> +
> +static int open_cpl_tracks(AVFormatContext *s) {
> + IMFContext *c = s->priv_data;
> + int32_t track_index = 0;
> + int ret;
> +
> + if (c->cpl->main_image_2d_track) {
> + if ((ret = open_virtual_track(s, c->cpl->main_image_2d_track,
> track_index++)) != 0) {
> + av_log(s, AV_LOG_ERROR, "Could not open image track "
> UUID_FORMAT "\n", UID_ARG(c->cpl->main_image_2d_track->base.id_uuid));
> + return ret;
> + }
> + }
> +
> + for (int audio_track_index = 0; audio_track_index <
> c->cpl->main_audio_track_count; ++audio_track_index) {
> + if ((ret = open_virtual_track(s,
> &c->cpl->main_audio_tracks[audio_track_index], track_index++)) != 0) {
> + av_log(s, AV_LOG_ERROR, "Could not open audio track "
> UUID_FORMAT "\n",
> UID_ARG(c->cpl->main_audio_tracks[audio_track_index].base.id_uuid));
> + return ret;
> + }
> + }
> +
> + return set_context_streams_from_tracks(s);
> +}
> +
> +static int imf_close(AVFormatContext *s);
> +
> +static int imf_read_header(AVFormatContext *s) {
> + IMFContext *c = s->priv_data;
> + char *asset_map_path;
> + int ret;
> +
> + c->base_url = av_dirname(av_strdup(s->url));
> +
> + av_log(s, AV_LOG_DEBUG, "start parsing IMF CPL: %s\n", s->url);
> +
> + if ((ret = parse_imf_cpl(s->pb, &c->cpl)) < 0)
> + goto fail;
> +
> + av_log(s, AV_LOG_DEBUG, "parsed IMF CPL: " UUID_FORMAT "\n",
> UID_ARG(c->cpl->id_uuid));
> +
> + if (!c->asset_map_paths) {
> + c->asset_map_paths = av_append_path_component(c->base_url,
> "ASSETMAP.xml");
> + }
> +
> + // Parse each asset map XML file
> + asset_map_path = strtok(c->asset_map_paths, ",");
> + while (asset_map_path != NULL) {
> + av_log(s, AV_LOG_DEBUG, "start parsing IMF Asset Map: %s\n",
> asset_map_path);
> +
> + if ((ret = parse_assetmap(s, asset_map_path, NULL)) < 0)
> + goto fail;
> +
> + asset_map_path = strtok(NULL, ",");
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "parsed IMF Asset Maps\n");
> +
> + if ((ret = open_cpl_tracks(s)) != 0) {
> + goto fail;
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "parsed IMF package\n");
> + return ret;
> +
> +fail:
> + imf_close(s);
> + return ret;
> +}
> +
> +static IMFVirtualTrackPlaybackCtx
> *get_next_track_with_minimum_timestamp(AVFormatContext *s) {
> + IMFContext *c = s->priv_data;
> + IMFVirtualTrackPlaybackCtx *track;
> +
> + AVRational minimum_timestamp = av_make_q(INT32_MAX, 1);
> + for (int i = 0; i < c->track_count; ++i) {
> + av_log(s, AV_LOG_DEBUG, "Compare track %d timestamp "
> AVRATIONAL_FORMAT " to minimum " AVRATIONAL_FORMAT " (over duration: "
> AVRATIONAL_FORMAT ")\n", i,
> AVRATIONAL_ARG(c->tracks[i]->current_timestamp),
> AVRATIONAL_ARG(minimum_timestamp), AVRATIONAL_ARG(c->tracks[i]->duration));
> + if (av_cmp_q(c->tracks[i]->current_timestamp, minimum_timestamp)
> < 0) {
> + track = c->tracks[i];
> + minimum_timestamp = track->current_timestamp;
> + }
> + }
> +
> + av_log(s, AV_LOG_DEBUG, "Found next track to read: %d (timestamp: %lf
> / %lf)\n", track->index, av_q2d(track->current_timestamp),
> av_q2d(minimum_timestamp));
> + return track;
> +}
> +
> +static IMFVirtualTrackResourcePlaybackCtx
> *get_resource_context_for_timestamp(AVFormatContext *s,
> IMFVirtualTrackPlaybackCtx *track) {
> + AVRational edit_unit_duration =
> av_inv_q(track->resources[0]->resource->base.edit_rate);
> + AVRational cumulated_duration = av_make_q(0, edit_unit_duration.den);
> +
> + av_log(s, AV_LOG_DEBUG, "Looking for track %d resource for timestamp
> = %lf / %lf\n", track->index, av_q2d(track->current_timestamp),
> av_q2d(track->duration));
> + for (int i = 0; i < track->resource_count; ++i) {
> + cumulated_duration = av_add_q(cumulated_duration,
> av_make_q((int)track->resources[i]->resource->base.duration *
> edit_unit_duration.num, edit_unit_duration.den));
> +
> + if (av_cmp_q(av_add_q(track->current_timestamp,
> edit_unit_duration), cumulated_duration) <= 0) {
> + av_log(s, AV_LOG_DEBUG, "Found resource %d in track %d to
> read for timestamp %lf (on cumulated=%lf): entry=%ld, duration=%lu,
> editrate=" AVRATIONAL_FORMAT " | edit_unit_duration=%lf\n", i,
> track->index, av_q2d(track->current_timestamp), av_q2d(cumulated_duration),
> track->resources[i]->resource->base.entry_point,
> track->resources[i]->resource->base.duration,
> AVRATIONAL_ARG(track->resources[i]->resource->base.edit_rate),
> av_q2d(edit_unit_duration));
> +
> + if (track->current_resource_index != i) {
> + av_log(s, AV_LOG_DEBUG, "Switch resource on track %d:
> re-open context\n", track->index);
> + if (track->resources[track->current_resource_index] !=
> NULL) {
> +
> avformat_close_input(&track->resources[track->current_resource_index]->ctx);
> + }
> + if (open_track_resource_context(s, track->resources[i])
> != 0) {
> + return NULL;
> + }
> + track->current_resource_index = i;
> + }
> + return track->resources[track->current_resource_index];
> + }
> + }
> + return NULL;
> +}
> +
> +static int ff_imf_read_packet(AVFormatContext *s, AVPacket *pkt) {
> + IMFContext *c = s->priv_data;
> +
> + IMFVirtualTrackResourcePlaybackCtx *resource_to_read = NULL;
> + AVRational edit_unit_duration;
> + int ret = 0;
> +
> + IMFVirtualTrackPlaybackCtx *track_to_read =
> get_next_track_with_minimum_timestamp(s);
> + FFStream* track_to_read_stream_internal;
> +
> + if (av_cmp_q(track_to_read->current_timestamp,
> track_to_read->duration) == 0) {
> + return AVERROR_EOF;
> + }
> +
> + resource_to_read = get_resource_context_for_timestamp(s,
> track_to_read);
> +
> + if (!resource_to_read) {
> + edit_unit_duration =
> av_inv_q(track_to_read->resources[track_to_read->current_resource_index]->resource->base.edit_rate);
> + if (av_cmp_q(av_add_q(track_to_read->current_timestamp,
> edit_unit_duration), track_to_read->duration) > 0) {
> + return AVERROR_EOF;
> + }
> +
> + av_log(s, AV_LOG_ERROR, "Could not find IMF track resource to
> read\n");
> + return AVERROR_STREAM_NOT_FOUND;
> + }
> +
> + while (!ff_check_interrupt(c->interrupt_callback) && !ret) {
> + ret = av_read_frame(resource_to_read->ctx, pkt);
> + av_log(s, AV_LOG_DEBUG, "Got packet: pts=%" PRId64 ", dts=%"
> PRId64 ", duration=%" PRId64 ", stream_index=%d, pos=%" PRId64 "\n",
> pkt->pts, pkt->dts, pkt->duration, pkt->stream_index, pkt->pos);
> + track_to_read_stream_internal =
> ffstream(s->streams[track_to_read->index]);
> + if (ret >= 0) {
> + // Update packet info from track
> + if (pkt->dts < track_to_read_stream_internal->cur_dts &&
> track_to_read->last_pts > 0) {
> + pkt->dts = track_to_read_stream_internal->cur_dts;
> + }
> +
> + pkt->pts = track_to_read->last_pts;
> + pkt->dts = pkt->dts -
> (int64_t)track_to_read->resources[track_to_read->current_resource_index]->resource->base.entry_point;
> + pkt->stream_index = track_to_read->index;
> +
> + // Update track cursors
> + track_to_read->current_timestamp =
> av_add_q(track_to_read->current_timestamp, av_make_q((int)pkt->duration *
> resource_to_read->ctx->streams[0]->time_base.num,
> resource_to_read->ctx->streams[0]->time_base.den));
> + track_to_read->last_pts += pkt->duration;
> +
> + return 0;
> + } else if (ret != AVERROR_EOF) {
> + av_log(s, AV_LOG_ERROR, "Could not get packet from track %d:
> %s\n", track_to_read->index, av_err2str(ret));
> + return ret;
> + }
> + }
> +
> + return AVERROR_EOF;
> +}
> +
> +static int imf_close(AVFormatContext *s) {
> + IMFContext *c = s->priv_data;
> +
> + av_log(s, AV_LOG_DEBUG, "Close IMF package\n");
> + av_dict_free(&c->avio_opts);
> + av_freep(&c->base_url);
> + imf_asset_locator_map_free(c->asset_locator_map);
> + imf_cpl_free(c->cpl);
> +
> + for (int i = 0; i < c->track_count; ++i) {
> + imf_virtual_track_playback_context_free(c->tracks[i]);
> + }
> +
> + return 0;
> +}
> +
> +static const AVOption imf_options[] = {
> + {"assetmaps", "IMF CPL-related asset map comma-separated absolute
> paths. If not specified, the CPL sibling `ASSETMAP.xml` file is used.",
> offsetof(IMFContext, asset_map_paths), AV_OPT_TYPE_STRING, {.str = NULL},
> 0, 0, AV_OPT_FLAG_DECODING_PARAM},
> + {NULL}};
> +
> +static const AVClass imf_class = {
> + .class_name = "imf",
> + .item_name = av_default_item_name,
> + .option = imf_options,
> + .version = LIBAVUTIL_VERSION_INT,
> +};
> +
> +const AVInputFormat ff_imf_demuxer = {
> + .name = "imf",
> + .long_name = NULL_IF_CONFIG_SMALL("IMF (Interoperable Master
> Format)"),
> + .priv_class = &imf_class,
> + .priv_data_size = sizeof(IMFContext),
> + .read_header = imf_read_header,
> + .read_packet = ff_imf_read_packet,
> + .read_close = imf_close,
> + .extensions = "xml",
> + .mime_type = "application/xml,text/xml",
> +};
> --
> 2.17.1
>
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