[FFmpeg-devel] [PATCH 3/5] avformat/imf: Demuxer implementation

Pierre-Anthony Lemieux pal at sandflow.com
Sun Oct 31 20:34:27 EET 2021


On Thu, Oct 28, 2021 at 12:58 AM Paul B Mahol <onemda at gmail.com> wrote:
>
>
>
> On Thu, Oct 28, 2021 at 6:32 AM Pierre-Anthony Lemieux <pal at sandflow.com> wrote:
>>
>> On Wed, Oct 27, 2021 at 12:54 AM Paul B Mahol <onemda at gmail.com> wrote:
>> >
>> >
>> >
>> > 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.
>>
>> The functions are not static and are defined in imf_internal.h. They
>> are used in both libavformat/imfdec.c and the tests at
>> libavformat/tests/imf.c. Ok?
>
>
> If they are used in libavformat only it should be static.

AFAIK static functions are only available in the compilation unit
where they are defined, so if a static function (e.g.
`parse_imf_asset_map_from_xml_dom()`) is defined in
libavformat/imf_dec.c, it will not be available in
libavformat/tests/imf.c.

Functions that can be used by other FFMPEG modules are declared in
"imf.h", whereas functions that are intended to be used only by the
IMF demuxer are declared in "imf_internal.h".

For example, both "libavformat/tests/imf.c" and "libavformat/imfdec.c"
include "libavformat/imf_internal.h" so they can access
`parse_imf_asset_map_from_xml_dom()`.

Does that work? Any alternative?

>
>>
>>
>> By bad code style, do you mean using brackets for a single if-statement?
>
>
> Look at style of other demuxers. Exp. '{' is not on same line as function name.

Got it. Will fix.

I have a clang format config file to perform automated formatting. Do
you think there would be interest in making it available to other
contributors?

>
>>
>>
>>
>> >
>> >
>> >> +    // 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
>> >>
>> >> _______________________________________________
>> >> ffmpeg-devel mailing list
>> >> ffmpeg-devel at ffmpeg.org
>> >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>> >>
>> >> To unsubscribe, visit link above, or email
>> >> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".


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